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Evoked potential in relation to subsequent alpha frequency.
A series of 24 visually evoked potentials was obtained from a normnal human subject under a set of unvarying experimental conditions. The 24 trials were ordered according to the alpha frequency subsequent to presentation of the stimulus. The evoked potentials fromt the 12 higher- and 12 lower-frequency trials were averaged separateb. These two average curves differed significantly at each of the six nodal points. | {
"pile_set_name": "PubMed Abstracts"
} |
Metabolism of 9-(1,3-dihydroxy-2-propoxymethyl)guanine, a new anti-herpes virus compound, in herpes simplex virus-infected cells.
The metabolism of 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG), one of the most promising new anti-herpes virus compounds, in HeLa cells infected with herpes simplex virus type 1 was compared with that in the uninfected HeLa cells. In the virus-infected cells, the uptake of DHPG was enhanced and the major metabolites were found to be the mono-, di-, and triphosphate derivatives. The formation of these metabolites was dependent on the extracellular concentration of DHPG (0.5 to 5.0 microM). Virus-induced thymidine kinase was capable of phosphorylating DHPG to its monophosphate which could be further phosphorylated to the di- and triphosphate derivatives by the host cellular enzymes. Incorporation of the DHPG into DNA was observed in virus-infected cells. In contrast with 9-(2-hydroxyethoxymethyl)guanine, DHPG seemed not to serve as a chain terminator, but to be incorporated internally into DNA strands. | {
"pile_set_name": "PubMed Abstracts"
} |
Determination of traces of iron(II) in the presence of iron(III) by the bathophenanthroline method.
Traces of iron(II) (1-30 ppM) in the presence of iron(III) were determined (error <10%) by the bathophenanthroline method. Interference of iron(III) was eliminated by masking with sodium pyrophosphate (2.5-60 mg). The iron(II) complex was extracted with n-butanol, at pH 4.2-4.7. | {
"pile_set_name": "PubMed Abstracts"
} |
Crystal Ball Gazing: Research and Clinical Work in Fluency Disorders in 2026.
In this article, the authors (with the assistance of colleagues from whom they solicited comments), provide a forward-looking perspective on research and clinical work in fluency disorders in the next 10-15 years. Issues discussed include neurology, genetics, early intervention, and clinical training in stuttering. | {
"pile_set_name": "PubMed Abstracts"
} |
Pain thresholds in rheumatoid arthritis: the effect of tender point counts and disease duration.
We evaluated the influence of demographic and clinical factors on pain thresholds in patients with rheumatoid arthritis (RA). A cross-sectional observational study (105 patients with RA) assessed pain thresholds using an algometer. Regression analysis examined the influence of demographic and clinical assessments. Pain thresholds (median 289, interquartile range 89-434) correlated with assessments of disease activity (tender joint counts), disability (Health Assessment Questionnaire), fatigue, depression, and anxiety. Ordinal logistic regression showed tender point counts and disease duration were the dominant contributors. These findings suggest that low pain thresholds reflect "fibromyalgic" RA (many tender points) and central pain sensitization with prolonged disease duration. | {
"pile_set_name": "PubMed Abstracts"
} |
Physiological and pathological responses of TU waves to class Ia antiarrhythmic drugs.
Abnormal repolarization associated with torsades de pointes is expressed as QT prolongation. The physiological response to class Ia antiarrhythmic drugs is also reflected in prolongation of the QT interval. However, the essential difference between pathological and physiological prolongation is not clear. The purpose of this investigation was to differentiate between pathological and physiological changes in the repolarization waves of surface electrocardiograms (ECG) induced by class Ia drugs. In 18 patients without a history of torsades de pointes or syncope (control group), TU waves were compared before and after the administration of class Ia drugs (physiological response). In eight patients with torsades de pointes induced by class Ia drugs (torsades de pointes group), the TU waves at torsades de pointes were compared with those before drug administration (pathological response). In the control group, although the QTc (measured in lead II and corrected for heart rate by Bazett's formula) was increased significantly (0.40 +/- 0.04 to 0.44 +/- 0.05 s, P < 0.001), the U-amp (amplitude of the U wave measured in a precordial lead where the T and U waves were clearly differentiated) remained unchanged. In the torsades de pointes group, however, the QTc was increased (0.42 +/- 0.04 to 0.54 +/- 0.07 s, P < 0.02); the U-amp was also increased, significantly (0.09 +/- 0.07 to 0.27 +/- 0.18 mV, P < 0.05). Thus, enlargement of the U wave may help to differentiate between the physiological and pathological responses to class Ia drugs. | {
"pile_set_name": "PubMed Abstracts"
} |
Insulin and glucagon regulation of gluconeogenesis in preruminating and ruminating bovine.
Hepatocyte monolayers were established from young preruminating (7 to 14 d of age) or older ruminating (11 to 12 wk of age) calves and used to evaluate the effects of insulin and glucagon on incorporation of carbon from 2.5 mM [2-14C]propionate and 2.0 mM [U-14C]lactate into glucose and glycogen. Developmental state (young preruminating vs older ruminating) of the donor calf did not affect the rate of gluconeogenesis from propionate in the absence of hormones. Insulin decreased (P < .05) gluconeogenesis and increased (P < .05) glycogenesis from propionate and lactate in hepatocytes from preruminating calves but had no effect on hepatocytes from ruminating calves. Lactate was poorly metabolized to glucose and was not responsive to glucagon in hepatocytes from ruminating calves compared with hepatocytes from preruminating calves. Hepatocytes responded to glucagon by increasing (P < .05) gluconeogenesis from propionate. Maximal responsiveness to glucagon did not differ between ruminating and preruminating calves, but hepatocytes from preruminating calves responded at lower glucagon concentrations (P < .05). These data demonstrate a similar capacity of hepatocytes from preruminating and ruminating calves to metabolize propionate to glucose, but there was a seven- to eightfold decrease in gluconeogenesis from lactate in ruminating calves that was accompanied by a decreased response to acute changes in insulin and glucagon. | {
"pile_set_name": "PubMed Abstracts"
} |
Soft drink consumption and urinary stone recurrence: a randomized prevention trial.
The object of this study was to determine if a strong association between soft drink (soda) consumption and recurrence of urinary stone disease, found in an earlier case-control study of adult males, had a causal component. The study sample consisted of 1009 male subjects, who completed an episode of urinary stone disease, who were aged 18-75 at that time, and who reported consuming at least 160 ml per day of soft drinks. Half of the subjects were randomized to refrain from consuming soft drinks, while the remaining subjects served as controls. The intervention group had an observed 6.4% advantage in actuarial 3 yr freedom from recurrence (p = 0.023 one-sided) over the control group. One important secondary finding was that for those who reported at the time of the index stone that their most consumed drink was acidified by phosphoric acid but not citric acid, the experimental group had a 15% higher 3 yr recurrence-free rate than the controls, p = 0.002, while for those who reported at the time of the index stone that their most consumed drink was acidified by citric acid with or without phosphoric acid, the experimental group had a similar 3 yr recurrence-free rate to the controls, p = 0.55. This interaction was significant, p = 0.019. | {
"pile_set_name": "PubMed Abstracts"
} |
A DNA resequencing array for pathogenic mutation detection in hypertrophic cardiomyopathy.
Hypertrophic cardiomyopathy (HCM) is a heterogeneous autosomal dominant cardiac disorder with a prevalence of 1 in 500. Over 450 different pathogenic mutations in at least 16 genes have been identified so far. The large allelic and genetic heterogeneity of HCM requires high-throughput, rapid, and affordable mutation detection technologies to efficiently integrate molecular screening into clinical practice. We developed a custom DNA resequencing array that contains both strands of all coding exons (160), splice-site junctions, and 5'UTR regions of 12 genes that have been clearly implicated in HCM (MYH7, MYBPC3, TNNT2, TPM1, TNNI3, MYL3, MYL2, CSRP3, PLN, ACTC, TNNC1, and PRKAG2). We analyzed a first series of 38 unrelated patients with HCM (17 familial, 21 sporadic). A total of 953,306 bp across the 38 patients were sequenced with a mean nucleotide call rate of 96.92% (range: 93-99.9%). Pathogenic mutations (single nucleotide substitutions) in MYH7, MYBPC3, TNNI3, and MYL3 (six known and six novel) were identified in 60% (10/17) of familial HCM and 10% of sporadic cases (2/21). The high-throughput HCM resequencing array is the most rapid and cost-effective tool for molecular testing of HCM to date; it thus has considerable potential in diagnostic and predictive testing, and prognostic stratification. | {
"pile_set_name": "PubMed Abstracts"
} |
Occurrence of unmyelinated axon profiles at distal, middle and proximal levels in the ventral root L7 of cats and kittens.
The proportion of unmyelinated axon profiles (UAP) was estimated electronmicroscopically at different proximo-distal levels in the ventral root L7 of 7 normal adult cats and 2 kittens. In 3 of the adult cats the occurrence of UAP was also determined in the juxtamedullary root fascicles, including the CNS/PNS transitional region. Three additional adult (male) cats, which had been subjected to prepubertal castration, were examined at mid-root level. Prepubertal castration was found not to interfere with the increase in L7 ventral root UAP that takes place during puberty. In the normal animals the proportion of UAP was highest distally in the ventral root and decreased as the spinal cord was approached. The same trend was seen in cats and kittens, but the values were obviously higher in adults. The content of UAP decreased markedly in the immediate vicinity of the CNS/PNS border. Very few unmyelinated axons and no myelinated CNS-type axons with sizes below the gamma range were found on the CNS side of this border. In addition groups of PNS-type unmyelinated and small myelinated axons occurred in the pia mater outside some juxtamedullary root fascicles. | {
"pile_set_name": "PubMed Abstracts"
} |
The population value of quality indicator reporting: a framework for prioritizing health care performance measures.
The Agency for Healthcare Research and Quality (AHRQ) National Healthcare Quality and Disparities Reports contain more than 250 quality indicators, such as whether a patient with a suspected heart attack received an aspirin. The Department of Health and Human Services National Quality Measures Clearinghouse identifies more than 2,100 such indicators. Because resources for making quality improvements are limited, there is a need to prioritize among these indicators. We propose an approach to assess how reporting specific quality indicators would change care to improve the length and quality of life of the US population. Using thirteen AHRQ quality indicators with readily available data on the benefits of indicator reporting, we found that seven of them account for 93 percent of total benefits, while the remaining six account for only 7 percent of total benefits. Use of a framework such as this could focus resources on indicators having the greatest expected impact on population health. | {
"pile_set_name": "PubMed Abstracts"
} |
A silver tattoo of the nasal mucosa after silver nitrate cautery.
We report a silver tattoo of the nasal mucosa that occurred after silver nitrate cautery for nasal bleeding. This type of tattoo is a very rare potential mimic of melanoma and appears not to have been described before. It has similar features to an amalgam tattoo of the oral mucosa on histology and energy dispersive X-ray analysis (EDAX). | {
"pile_set_name": "PubMed Abstracts"
} |
Altered Low-Frequency EEG Connectivity in Mild Cognitive Impairment as a Sign of Clinical Progression.
Mild cognitive impairment (MCI) is associated with clinical progression to Alzheimer's disease (AD) but not all patients with MCI convert to AD. However, it is important to have methods that can differentiate between patients with MCI who progress (pMCI) and those who remain stable (sMCI), i.e., for timely administration of disease-modifying drugs. In the current study, we wanted to investigate whether quantitative EEG coherence and imaginary part of coherency (iCoh) could be used to differentiate between pMCI and sMCI. 17 patients with AD, 27 patients with MCI, and 38 older healthy controls were recruited and followed for three years and 2nd year was used to determine progression. EEGs were recorded at baseline and coherence and iCoh were calculated after thorough preprocessing. Between pMCI and sMCI, the largest difference in total coherence was found in the theta and delta bands. Here, the significant differences for coherence and iCoh were found in the lower frequency bands involving the temporal-frontal connections for coherence and parietal-frontal connections for iCoh. Furthermore, we found a significant negative correlation between theta coherence and the Addenbrooke's Cognitive Examination (ACE) (p = 0.0378; rho = -0.2388). These findings suggest that low frequency coherence and iCoh can be used to determine, which patients with MCI will progress to AD and is associated with the ACE score. Low-frequency coherence has previously been associated with increased hippocampal atrophy and degeneration of the cholinergic system and may be an early marker of AD pathology. | {
"pile_set_name": "PubMed Abstracts"
} |
Treatment of blood-induced glaucoma by trans pars plana vitrectomy.
Three patients are described who presented with blood-induced glaucoma. The cause of the vitreous hemorrhage was different for each patient, and included branch vein occlusion, diabetic retinopathy, and cataract extraction. The clinical findings common to all three cases consisted of degenerated red blood cells in the anterior chamber and vitreous cavity, a broken anterior vitreous face, open angles, and the absence of rubeosis iridis. Pars plana vitrectomy and anterior chamber irrigation resulted in normalization of intraocular pressure in each patient. | {
"pile_set_name": "PubMed Abstracts"
} |
Making sense of federal GME reforms: the need for secondary reforms.
Physician workforce issues in the healthcare reform debate have led to considerable agreement on the need to reform graduate medical education (GME) in order to control the cost, mix and supply of physician manpower. The osteopathic medical profession's infrastructure is ill-prepared to respond to many of the changes that policymakers are suggesting. In last month's issue, the author reviewed the Gephardt and Mitchell bills, which emerged during the last Congress, identified the reforms recommended for GME, and examined the elements of agreement between the bills. The position of osteopathic medicine vis-à-vis healthcare reform was explored and distinctions between the two bills were drawn. In this article, the author recommends comprehensive secondary reforms in the osteopathic medical profession's three institutions--its colleges, its hospitals, and its political organization, the American Osteopathic Association. | {
"pile_set_name": "PubMed Abstracts"
} |
Novel Conductive Filament Metal-Interlayer-Semiconductor Contact Structure for Ultralow Contact Resistance Achievement.
In the post-Moore era, it is well-known that contact resistance has been a critical issue in determining the performance of complementary metal-oxide-semiconductor (CMOS) reaching physical limits. Conventional Ohmic contact techniques, however, have hindered rather than helped the development of CMOS technology reaching its limits of scaling. Here, a novel conductive filament metal-interlayer-semiconductor (CF-MIS) contact-which achieves ultralow contact resistance by generating CFs and lowering Schottky barrier height (SBH)-is investigated for potential applications in various nanodevices in lieu of conventional Ohmic contacts. This universal and innovative technique, CF-MIS contact, forming the CFs to provide a quantity of electron paths as well as tuning SBH of semiconductor is first introduced. The proposed CF-MIS contact achieves ultralow specific contact resistivity, exhibiting up to ∼×700 000 reduction compared to that of the conventional metal-semiconductor contact. This study proves the viability of CF-MIS contacts for future Ohmic contact schemes and that they can easily be extended to mainstream electronic nanodevices that suffer from significant contact resistance problems. | {
"pile_set_name": "PubMed Abstracts"
} |
Peri-operative care.
This is the third 'midwifery basics' series aimed at student midwives, and focuses on midwifery care during labour. This article provides a summary of peri-operative care for women who experience caesarean birth. Students are encouraged to seek further information through a series of activities, and to link theory with practice by considering the issues relating to the care of the woman described in the short vignette. | {
"pile_set_name": "PubMed Abstracts"
} |
An internal distraction device for Le Fort distraction osteogenesis: the NAVID system.
Le Fort distraction osteogenesis is sometimes applied to improve the facial appearance in craniofacial dysostosis or cleft lip and palate. Distraction devices are generally classified into external and internal types. The movement of external distractors can be controlled easily but their large size and the need for a facial mask cause much psychological stress to the patient. Internal distractors are smaller and better tolerated, but they are not easily controllable and removal is difficult. We designed an internal distraction device to eliminate the problems of the currently available distractors -Nakajima's angle-variable internal distraction (NAVID) system - and aimed to assess its clinical applicability. Between 2000 and 2010, we treated 16 patients with the NAVID system: Le Fort I, III, III + I and IV distractions were performed in three, five, four and four patients, respectively. Distraction was started after a 1-week latency period. Then, the exposed rod was cut, and the distractors were left in place for 3 months or more as retention devices, and thereafter removed. All patients showed satisfactory occlusion and facial aesthetics. Open bite during the consolidation period was the main complication. In conclusion, the NAVID system is safe, effective and reliable for all types of Le Fort distraction osteogenesis. | {
"pile_set_name": "PubMed Abstracts"
} |
Abnormal functional connectivity in posttraumatic stress disorder.
This study investigated the efficacy of a combined multivariate/resampling procedure for the analysis of PET activation studies. The covariance-based multivariate analysis was used to investigate distributed brain systems in posttraumatic stress disorder (PTSD) patients and matched controls during performance of a working memory task. The results were compared to univariate results obtained in an earlier study. We also examined whether the PTSD patients demonstrated a breakdown in functional connectivity that may be associated with working memory difficulties often experienced by these patients. A resampling procedure was used specifically to test the reliability of measured between-group effects, to avoid mistaken inference on the basis of random intersubject differences. Significant and reproducible differences in network connectivity were obtained for the two groups. The functional connectivity pattern of the patient group was characterized by relatively more activation in the bilateral inferior parietal lobes and the left precentral gyrus than the control group, and less activation in the inferior medial frontal lobe, bilateral middle frontal gyri and right inferior temporal gyrus. The resampling procedure provided direct evidence that working memory updating was abnormal in PTSD patients relative to matched controls. This work focuses on the need to identify extended brain networks (in addition to regionally specific changes) for the full characterization of brain responses in neuroimaging experiments. Our multivariate analysis explicitly measures the reliability of the patterns of functional connectivity we obtain and demonstrates the potential of such analyses for the study of brain network dysfunction in psychopathology. | {
"pile_set_name": "PubMed Abstracts"
} |
Human immunodeficiency virus infection in pregnancy.
Human immunodeficiency virus (HIV) infection in women is an increasing problem. World wide, at least 25% of all infections occur in adolescent or adult women, most of whom are of child-bearing age. The commonest modes of acquisition of HIV infection are sexual contact with an HIV-infected male and sharing needles during injecting drug use. Vertical transmission is the major route of HIV infection in infants and children and can occur in utero, intrapartum, through exposure to infected blood or secretions, or post partum, via breast milk. HIV infection has not been demonstrated to affect fertility, or to influence the outcome of pregnancy unless there is evidence of significant immune dysfunction, with CD4 counts below 400/mm3. Though data are limited, pregnancy does not appear to affect the course of HIV infection. Low CD4 counts predispose women to the opportunistic infectious complications of HIV. Pathogens include Candida sp., Mycobacterium tuberculosis, Pneumocystis carinii, Toxoplasma gondii, Cryptococcus neoformans and Cryptosporidium. These pathogens require early recognition and diagnosis if optimal treatment and outcome are to be attained. Treatment with zidovudine and prophylaxis against Pneumocystis carinii are appropriate when CD4 counts are less than 200/mm3, though the safety of zidovudine in early pregnancy is not known. Similarly it is not known whether zidovudine treatment of the mother prevents transmission of HIV infection to her baby. Caesarean section does not prevent peripartum transmission of HIV and should be undertaken only for other appropriate indications. The utility of antenatal screening for HIV depends upon the seroprevalence in the population. Such programmes must be supported by comprehensive clinical care as well as sensitive and non-judgemental counselling. | {
"pile_set_name": "PubMed Abstracts"
} |
Prevention of exposure to bloodborne pathogens.
This article is an overview of the bloodborne pathogen standard for podiatric practice. Included are the history of regulation, prevention measures to be undertaken in medical practice for the transmission of bloodborne pathogens, and measures for appropriate follow-up, should exposure occur. Physical, chemical, thermal, and procedural barriers against transmission and recommendations for the development of an office infection-control program are discussed. | {
"pile_set_name": "PubMed Abstracts"
} |
Erratum: Transport coefficients for driven granular mixtures at low density [Phys. Rev. E 88, 052201 (2013)] and Heat flux of driven granular mixtures at low density: Stability analysis of the homogeneous steady state [Phys. Rev. E 97, 022902 (2018)].
This corrects the article DOI: 10.1103/PhysRevE.97.022902. | {
"pile_set_name": "PubMed Abstracts"
} |
Distribution of Anti-Factor Xa Activity in Patients on Edoxaban Therapy for Non-Valvular Atrial Fibrillation.
The distribution of anti-factor Xa activity (AXA) values in non-valvular atrial fibrillation (NVAF) patients on edoxaban therapy has not been fully elucidated. The steady-state trough and peak AXA values were measured in 66 NVAF patients. The trough AXA value did not differ significantly between the 60-mg and the 30-mg OD groups (0.17±0.13 IU/ml vs. 0.12±0.11 IU/ml, respectively; P=0.17). Similarly, the peak AXA value did not differ significantly between the 2 groups (1.45±0.81 IU/ml vs. 1.25±0.48 IU/ml, respectively; P=0.26). Recommended dosing should be followed for sufficient efficacy of edoxaban. (Circ J 2016; 80: 745-747). | {
"pile_set_name": "PubMed Abstracts"
} |
Maintenance of pathogenic Th2 cells in allergic disorders.
Immunological memory is an important protective mechanism that enables host organisms to respond rapidly and vigorously to pathogens that have been previously encountered. In addition to the protective function, memory CD4+ T helper (Th) cells play a central role in the pathogenesis of chronic inflammatory disorders, including asthma. Recently, several investigators have identified phenotypically and functionally distinct memory Th2 cell subsets that produce IL-5. These memory Th2 cell subsets play an important role in the pathology of allergic inflammation and function as memory-type "pathogenic Th2 (Tpath2) cells" both in mice and humans. We review the role of lung Tpath2 cells in the development of allergic inflammation and, in the context of recent findings, propose a mechanism by which Tpath2 cells not only survive but also continue to function at the sites where antigens were encountered. A greater understanding of the functional molecules or signaling pathways that regulate the inflammatory niche for Tpath2 cells may aid in the design of more effective treatments for chronic inflammatory disorders. | {
"pile_set_name": "PubMed Abstracts"
} |
Lesions of the petrous apex: diagnosis and management.
Management of petrous apex pathology poses a unique challenge even to the most seasoned skull base surgeons. The central location in the skull base with adjacent critical neurovascular structures makes access to this region more than a trivial matter. Significant advances in diagnostic imaging have greatly facilitated the diagnosis of petrous apex lesions. The introduction of modern skull base surgery techniques also has provided skull base surgeons with numerous avenues to the petrous apex while significantly decreasing morbidity. The latest diagnostic and management strategies are discussed and an update of some of the more common pathologic entities is provided. | {
"pile_set_name": "PubMed Abstracts"
} |
Highly-efficient coupling of linearly- and radially-polarized femtosecond pulses in hollow-core photonic band-gap fibers.
We demonstrate extremely efficient excitation of linearly-, radially-, and azimuthally-polarized modes in a hollow-core photonic band-gap fiber with femtosecond laser pulses. We achieve coupling efficiencies as high as 98% with linearly polarized input Gaussian beams and with high-power pulses we obtain peak intensities greater than 10(14) W/cm(2) inside and transmitted through the fiber. With radially polarized pulses, we achieve 91% total transmission through the fiber while maintaining the polarization state. Alternatively with azimuthally-polarized pulses, the mode is degraded in the fiber, and the pure polarization state is not maintained. | {
"pile_set_name": "PubMed Abstracts"
} |
Robust and Sparse Linear Discriminant Analysis via an Alternating Direction Method of Multipliers.
In this paper, we propose a robust linear discriminant analysis (RLDA) through Bhattacharyya error bound optimization. RLDA considers a nonconvex problem with the L₁-norm operation that makes it less sensitive to outliers and noise than the L₂-norm linear discriminant analysis (LDA). In addition, we extend our RLDA to a sparse model (RSLDA). Both RLDA and RSLDA can extract unbounded numbers of features and avoid the small sample size (SSS) problem, and an alternating direction method of multipliers (ADMM) is used to cope with the nonconvexity in the proposed formulations. Compared with the traditional LDA, our RLDA and RSLDA are more robust to outliers and noise, and RSLDA can obtain sparse discriminant directions. These findings are supported by experiments on artificial data sets as well as human face databases. | {
"pile_set_name": "PubMed Abstracts"
} |
Allogeneic marrow transplantation for children with juvenile chronic myelogenous leukemia.
Fourteen children between the ages of 2 and 5 years with juvenile chronic myelogenous leukemia were given cyclophosphamide, total-body irradiation, and marrow transplants. Unmodified marrow was given to six patients who received marrow from HLA-identical siblings and eight patients who received marrow from family members HLA identical for one haplotype but mismatched for one to three loci on the nonshared haplotype. Five patients died of transplant-related complications, and three relapsed at 48, 81, and 1,670 days posttransplant and died of leukemia. Six patients survive in continuous remission from 0.5 to 11.5 years posttransplant. | {
"pile_set_name": "PubMed Abstracts"
} |
The validation and application of a finite element human head model for frontal skull fracture analysis.
Traumatic head injuries can result from vehicular accidents, sports, falls or assaults. The current advances in computational methods and the detailed finite element models of the human head provide a significant opportunity for biomechanical study of human head injuries. The biomechanical characteristics of the human head through head impact scenarios can be studied in detail by using the finite element models. Skull fracture is one of the most frequent occurring types of head injuries. The purpose of this study is to analyse the experimental head impacts on cadavers by means of the Strasbourg University Finite Element Head Model (SUFEHM). The results of the numerical model and experimental data are compared for validation purpose. The finite element model has also been applied to predict the skull bone fracture in frontal impacts. The head model includes the scalp, the facial bone, the skull, the cerebral spinal fluid, the meninges, the cerebrum and the cerebellum. The model is used to simulate the experimental frontal head impact tests using a cylindrical padded impactor. Results of the computational simulation shows that the model correlated well with a number of experimental data and a global fracture pattern has been predicted well by the model. Therefore the presented numerical model could be used for reconstruction of head impacts in different impact conditions also the forensic application of the head model would provide a tool for investigation of the causes and mechanism of head injuries. | {
"pile_set_name": "PubMed Abstracts"
} |
Distribution of astigmatism as a function of age in an Australian population.
Astigmatism is a common cause of refractive error and is known to vary in prevalence with age. Although the search for genes associated with spherical refractive errors (especially myopia) has met with limited success, current efforts to identify genetic variants implicated in astigmatism development have been less rewarding. We aimed to assess the association between astigmatism and age to identify appropriate age cut-offs for maximizing power in genetic studies of astigmatism. We performed a cross-sectional analysis of right eye astigmatism data from four Australian-based eye studies comprising 3841 participants aged 5-90 years. Measurements were performed under cycloplegia using an autorefractor, and individuals with a history of cataract, refractive surgery or corneal pathology were excluded from the analysis. In addition to the magnitude and type (against-the-rule, with-the-rule, and oblique) of astigmatism, we calculated the vector components (J0 , J45 ) and evaluated the association of these outcome measures with age. The magnitude of refractive astigmatism (RA) remained relatively stable [mean ± SD (-0.44 D ± 0.50)] until individuals reached the age of 50, thereafter increasing in average magnitude by approximately 1.00 D for those subjects aged 90. In contrast, corneal astigmatism (CA) remained relatively stable from childhood until the age of 80 (-0.76 D ± 0.61). The prevalence of clinically significant RA (≥1.00 D) increased with age and was highest in those aged >70 years [55.1% (47.2-62.7%)]. Age was significantly associated with RA in adults [odds ratio (OR) = 1.04 per 1 year, p < 0.001]. A weaker relationship was observed between CA and age (OR = 1.007 per 1 year, p = 0.02). We have confirmed the previously documented association between RA and age. Our results indicate that most of the observed change occurs after the age of 50, providing a recommended cut-off for participants in genetic studies of this refractive condition. | {
"pile_set_name": "PubMed Abstracts"
} |
Postoperative desogestrel for pelvic endometriosis-related pain: a randomized controlled trial.
To determine the effectiveness of desogestrel for relieving endometriosis-related pain. A double-blinded randomized placebo-controlled trial was conducted in 40 patients who had endometriosis with moderate-to-severe dysmenorrhea or chronic pelvic pain undergoing laparoscopic conservative surgery. After surgery, patients were randomized to desogestrel or placebo group. Outcomes included changes in visual analog scale (VAS) of dysmenorrhea, pelvic pain and dyspareunia, patient satisfaction, and adverse effects. Forty patients were randomized to desogestrel group (n = 20) and placebo group (n = 20). At month 6, the desogestrel group had significantly lower median VAS of overall pelvic pain, dysmenorrhea and noncyclic pelvic pain. Comparing with the placebo group, the desogestrel group had greater reduction in VAS of overall pain, dysmenorrhea and pelvic pain, but comparable reduction in VAS of dyspareunia. No patient in the desogestrel group but 4 patients in the placebo group still had moderate-to-severe pelvic pain at 6 months postoperatively. The proportion of patients who rated the treatment as very satisfied was higher in the desogestrel group than in the placebo group. There was no serious adverse event during the study period. Desogestrel is effective and acceptable for postoperative therapy for patients with moderate-to-severe pain related to endometriosis. | {
"pile_set_name": "PubMed Abstracts"
} |
Spinal subdural hematoma: a case report and literature review.
Spinal subdural hematoma (SSH) is an uncommon entity. There is a higher incidence among patients with a bleeding diathesis and among those with a bleeding diathesis having a lumbar puncture. The case reported here is of a 65-year-old woman on oral anticoagulants presenting with atypical symptoms who developed SSH over a six-hour period. Emergency investigation and treatment are required because recovery is inversely related to the length of time of spinal cord compression. A review of the literature revealed 37 previously reported cases of nonmajor traumatic SSH. | {
"pile_set_name": "PubMed Abstracts"
} |
[A case report of factitious disorder with hallucinations].
Although factitious disorder has been known for a long time, its diagnosis and treatment continue to be a problem. It is an uncommon condition associated with considerable morbidity and health care expenditure. We present a case of factitious disorder with hallucinations. A 37 year-old single woman has had auditory and olfactory hallucinations for six years. She had been diagnosed with schizophrenia, hospitalized for a short term, taking classical antipsychotic drugs for years. She has been performing her job as a teacher and living with her family. A suitable dose of atypical antipsychotic drugs was administered at a convenient time for her illness (Psychotic Disorder NOS) in psychiatric outpatient clinic of Kocaeli University. She was admitted to inpatient clinic twice in order to allow a clear diagnosis to be made. Psychotic disorder and temporal lobe epilepsy were ruled out. Borderline and histrionic personality traits were determined. Her complaints were unchanged over the course of treatment taking three years. She later started to come into the emergency department with anxiety symptoms, conversion like fits and suicide attempts; hospitalized for these complaints in another hospital. She was diagnosed with factitious disorder because of her unchanged complaints, her adding new complaints to the old ones, her complaints unrelated to psychosocial stressors, her ambitions to come to hospital, her increasing hospital dependence and having no prominent secondary gain. This case emphasizes the need for the careful observation of patients to prevent unnecessary investigations at the diagnosis and treatment stage and to establish a specific management strategy for the patients. | {
"pile_set_name": "PubMed Abstracts"
} |
Cost-effectiveness of pergolide compared to bromocriptine in the treatment of Parkinson's disease: a decision-analytic model.
To develop a decision-analytic model to assess the cost-effectiveness of pergolide versus bromocriptine in the treatment of Parkinson's disease (PD). A Markov decision-analytic model is used to examine cost-effectiveness. The model ran for 20 cycles of 6 months' duration, and the patients progress through six stages: Hoehn-Yahr stages 1-5 and death. The transitional probabilities for each stage are derived from a 12-year longitudinal study of patients with PD. The costs in the model are derived from an expert panel containing six Australian neurologists. A review of the randomized controlled trials comparing the efficacy and safety of pergolide versus bromocriptine was undertaken. Five studies were identified, with four showing that pergolide offers superior efficacy when compared to bromocriptine. The Mizuno et al. (1995) study was the largest of the controlled trials and also measured patient Hoehn-Yahr status before and after treatment. This was identified as the most appropriate source of relative efficacy data for the model. The model examined various scenarios based on alternate durations of superior clinical benefit with pergolide compared to bromocriptine. The main analysis assumed that patients in each arm of the model would have identical Hoehn-Yahr status by the fifth year. Sensitivity analysis was used to determine cost-effectiveness in the case where the therapeutic benefit was of a shorter duration. The Mizuno study indicates that an additional 19.09% of patients improved by at least one stage on pergolide over bromocriptine, with an odds ratio of 2.26 (p < .01). The total health care cost per patient over the 10-year period was $46,323 in the pergolide treatment arm and $47,351 in the bromocriptine treatment arm, an incremental saving of $1028. Patients also spent extra time in Hoehn-Yahr stages 1, 2, and 3. In sensitivity analyses, when the benefit from pergolide expired between 6 months and 5 years after treatment cessation, cost savings ranged from $68 to $2535. Pergolide is cost saving and more efficacious than bromocriptine, and is therefore cost-effective. | {
"pile_set_name": "PubMed Abstracts"
} |
PATTERNS OF ULTRASOUND FINDINGS IN ABDOMINAL LYMPHOMA PATIENTS AT TIKUR ANBESSA SPECIALIZED HOSPITAL, ADDIS ABABA, ETHIOPIA.
Malignant lymphoma is a common primary hematopoietic malignancy. Cross sectional imaging is used commonly. The wide spread availability and diagnostic potential of ultrasound (US) place it at the forefront in the setting of resource limited countries that do not have access to the full range of imaging modalities and in which patients frequently present in the late stages of diseases. Assess the patterns of abdominal organ involvement and ultrasound findings in patients with abdominal lymphoma. 69 consecutive patients who came to the US unit of Tikur Anbessa Specialized Hospital (TASH) with the diagnosis of lymphoma were scanned. All examinations were performed by the authors based on standard scanning techniques. Cine and spot images were stored for analysis and finding recorded on a preprepared and pretested format. Eighty nine percent of the patients were below the age of 60 and 75% were males. Chest x-ray and US were the modalities commonly used, while only 6 of 69 had computed tomography (CT) scans. Non-Hodgkin's lymphoma account for 81% of the cases. Lymph nodes were the most common organ involved and abdominal nodes accounted for 61% of the cases. Homogenous and hypoechoic echo appearances were seen in 52% and their pattern of involvement comprised multiple discrete nodes. Comparable overall patterns of involvement were seen in both pathologically confirmed and unconfirmed lymphoma cases. Liver followed by spleen was the most common abdominal organ involved, and organ enlargement and/or multiple variable sized hypoechoic lesions were the most common US findings. Our study emphasizes the continued role of US for lymphoma patients. The US findings and pattern of organ involvement was found to be comparable with previous studies. | {
"pile_set_name": "PubMed Abstracts"
} |
Slope efficiency measurements of a chromium-doped forsterite laser.
The slope efficiency of the continuous-wave chromium-doped forsterite (Cr:Mg(2)SiO(4)) laser has been measured by using four different output mirrors. The maximum slope efficiency of 38% was achieved with an 11% output coupler. The extrapolated limiting slope efficiency in the absence of passive losses is estimated to be 65%. This value corresponds to an intrinsic quantum efficiency of 77%, which is similar to the efficiencies determined for mature tunable solid-state laser systems. | {
"pile_set_name": "PubMed Abstracts"
} |
Review article: the effectiveness of standard triple therapy for Helicobacter pylori has not changed over the last decade, but it is not good enough.
BACKGROUND A decrease in the Helicobacter pylori eradication rate after standard triple therapy has been suggested in recent years. AIM To assess the efficacy of standard triple therapy in the eradication of H. pylori through an epidemiological analysis of all published Spanish trials. A secondary aim was to review the prevalence of clarithromycin resistance in Spain. METHODS Articles on H. pylori eradication in Spain published in peer-reviewed journals were identified through MEDLINE searches. Studies that included a triple therapy consisting of any proton pump inhibitor with clarithromycin (500 mg b.d.) and amoxicillin (1 g b.d.) for up to 14 days were selected. Spanish studies evaluating the prevalence of clarithromycin resistance were also reviewed. Meta-analysis was performed using the generic inverse variance method. RESULTS The pooled eradication rates by year from Spanish studies evaluating the efficacy of the standard triple regimen revealed a relatively constant rate over the years. Overall, the analysis of the 32 studies (4727 patients) showed a mean H. pylori cure rate of 80% (95% CI = 77-82%) by intention-to-treat and 83% (81-86%) by per-protocol. When only peptic ulcer disease or 7-day regimens were considered, results were similar. Based on 13 studies (3293 patients), mean clarithromycin resistance rate was 8% (5-10%). CONCLUSION Although a decrease in the H. pylori eradication rate after triple therapy has been suggested in recent years, cure rates with this regimen did not change in Spain between 1997 and 2008. However, this by no means indicates that the efficacy of standard triple therapy in Spain is acceptable, as it has been calculated to be around only 80%. Therefore, it is evident that new strategies to improve first-line treatment are urgently needed. | {
"pile_set_name": "PubMed Abstracts"
} |
Influence of performance level on exercise-induced arterial hypoxemia during prolonged and successive exercise in triathletes.
To study the relationship between performance and exercise-induced arterial hypoxemia (EIAH), 5 internationally ranked (INT) and 8 regionally ranked (REG) triathletes performed cycle-run successions (CR) and control runs (R) in competition-like conditions: at approximately 75% VO2max. Ventilatory parameters and oxyhemoglobin saturation (SpO2) data were collected continuously. Arteriolized partial pressure in O2 (PaO2) and alveolar ventilation (VA) were measured before and after cycling (CRcycle), the successive run (CRrun), and R. Pulmonary diffusing capacity (DLco) was measured at rest and 10 minutes post-CR. Training and short-distance triathlon data were collected. INT showed significantly greater experience than REG in competition years (P>.05), training regimen (P>.05), and swimming (P>.05), and cycling (P>.05) volumes; running showed a trend (P<.06). Cycling, running, and total triathlon performances were significantly higher in INT than REG (P>.01). SpO2 during CR dropped significantly more in INT than in REG. Both groups showed significant inverse correlations between the magnitude of the SpO2 change from CRcycle to CRrun and the triathlon running time (r=-0.784; P<.05 and r=-0.699; P<.05; respectively). When compared with CRcycle, PaO2 significantly decreased and VA significantly increased after CRrun and R in both groups (P<.01). DLco significantly dropped between pre- and postexercise in CR and R with no between-group difference (P<.05). EIAH was aggravated in higher performers during simulated cycle-run segments, related to longer experience and heavier training regimens. Possibly, relative hypoventilation caused this aggravated EIAH in INT, although pulmonary diffusion limitation was observed in both groups. Beyond EIAH severity, the magnitude of SpO2 variations during the cycle-run transition may affect triathlon running performance. | {
"pile_set_name": "PubMed Abstracts"
} |
A computational fluid dynamics model of viscous coupling of hairs.
Arrays of arthropod filiform hairs form highly sensitive mechanoreceptor systems capable of detecting minute air disturbances, and it is unclear to what extent individual hairs interact with one another within sensor arrays. We present a computational fluid dynamics model for one or more hairs, coupled to a rigid-body dynamics model, for simulating both biological (e.g., a cricket cercal hair) and artificial MEMS-based systems. The model is used to investigate hair-hair interaction between pairs of hairs and quantify the extent of so-called viscous coupling. The results show that the extent to which hairs are coupled depends on the mounting properties of the hairs and the frequency at which they are driven. In particular, it is shown that for equal length hairs, viscous coupling is suppressed when they are driven near the natural frequency of the undamped system and the damping coefficient at the base is small. Further, for certain configurations, the motion of a hair can be enhanced by the presence of nearby hairs. The usefulness of the model in designing artificial systems is discussed. | {
"pile_set_name": "PubMed Abstracts"
} |
Effects of glyphosate and aminomethylphosphonic acid on an isogeneic model of the human blood-brain barrier.
Glyphosate is a pesticide used for occupational and non-occupational purposes. Because glyphosate targets a metabolic pathway absent in animals, it is considered safe for humans. Yet, case reports of accidental exposure to concentrated solutions following self-inflicted poisoning documented neurological lesions suggesting a neurotoxicity. In this study, we investigated the effect of acute exposure to glyphosate (GPH) on the blood-brain barrier in vitro based on induced pluripotent stem cells (iPSCs) and compared to two chemical analogs: aminomethylphosphonic acid (AMPA) and glycine (GLY), for concentrations ranging from 0.1 μM to 1000 μM. GPH treatment (1 and 10 μM) for 24 h showed an increase BBB permeability to fluorescein, with similar outcomes for AMPA. In addition to its ability to disrupt the barrier function, GPH show evidence of permeability across the BBB. Although no detrimental effects were observed on neuron differentiation at high doses, we noted changes in neuronal cell metabolic activity and glucose uptake in brain microvascular endothelial cells (BMECs) following treatment with 100 μM GPH or AMPA. Taken together, our data indicates that accidental exposure to high level of GPH may result in neurological damage via an opening of the blood-brain barrier and an alteration of glucose metabolism. | {
"pile_set_name": "PubMed Abstracts"
} |
Sexually transmitted infections in women infected with the human immunodeficiency virus. Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA).
Limited prospective data are available on sexually transmitted infections (STIs) among HIV-infected patients. The incidence and predictors of STIs were assessed among HIV-infected women enrolled in a clinical trial. Prospective cohort of 323 women. Sixty-five percent had at least one STI based on history and/or examination at baseline. Most conditions identified at baseline were based on patient history; only 10 of 123 women with no history of an STI (8.1%) had one identified upon examination. During a median follow-up of 2.1 years, 25% developed a new/recurrent STI. Being African-American (odds ratio [OR] = 4.22, 95% confidence interval [CI]: 1.45-12.26), reporting sex with an intravenous drug user as an HIV risk behavior (OR = 2.29, 95% CI: 1.34-3.92), and a history/presence of STIs at baseline (OR = 1.79, 95% CI: 1.01-3.19) were factors associated with significantly increased risk of STI's. A substantial proportion of women developed new STIs during the course of the clinical trial. Prevention efforts should be emphasized among high risk HIV-infected patients. | {
"pile_set_name": "PubMed Abstracts"
} |
Application of an indwelling vascular access port for intravenous administration in a repeated and intermittent dose toxicity study in rats.
Totally implantable catheter animal models are considered useful for pharmacological and toxicological studies. In this report, we assessed the feasibility of using an indwelling vascular access port (VAP) in rats for long-term evaluation of repeated and intermittent dose toxicity studies. In Experiment 1, the VAP devices were implanted in male and female rats and a saline solution administered intravenously via the posterior vena cava for 2 weeks (4 ml/kg, 2 ml/min, 5 times/week, 10 times total). General conditions, body weight and blood chemistry showed no toxicological changes compared with the rats in the non-implanted, non-treated group. Hematology changes such as transient increases in peripheral blood reticulocytes and eosinophils were noted post-implantation. In pathology, proliferation of the endothelium at the site of VAP implantation and perivascular inflammatory cell infiltration including eosinophils in lung were noted at the end of the treatment period. Moreover, we found that the lumbar area is more suitable for VAP implantation than the back of neck for young, still growing rats. Experiment 2 included a 1-month intravenous intermittent dose (4 ml/kg, 2 ml/min, 1 time/week, 5 times total) toxicity study in VAP-implanted rats followed by a 1-month recovery period conducted under Good Laboratory Practice (GLP) regulations. The results suggested that an animal model with implanted VAP is useful for intermittent intravenous dosing of drugs. Moreover, VAP implantation in animals is expected to be extrapolated to use VAP in humans in clinical studies. | {
"pile_set_name": "PubMed Abstracts"
} |
Mild ventriculomegaly detected in utero with ultrasound: clinical associations and implications for schizophrenia.
The most consistent structural abnormality of the brain associated with schizophrenia is that of mild enlargement of the lateral cerebral ventricles. Mild ventriculomegaly (MVM) of the fetal brain detected in utero with ultrasound is associated with developmental delays similar to those described in children at high risk of schizophrenia. Fetal mild ventriculomegaly may be a marker for increased risk of schizophrenia and other neurodevelopmental abnormalities. Given the association between schizophrenia and obstetrical complications, pre- and perinatal complications and pregnancy outcomes were retrospectively reviewed in 51 pregnancies in which the fetus exhibited mild ventriculomegaly on routine ultrasonography and 49 control pregnancies. Mothers of children with MVM were older than controls and had shorter gestations. There were no significant between-group differences in numbers of pregnancy complications or pregnancy outcomes as reflected in gestational age at birth, birthweight, or Apgar scores. Children with isolated mild ventriculomegaly tended to be male. This study indicates that isolated mild ventriculomegaly detected in utero is not associated with pregnancy complications and suggests that isolated mild ventriculomegaly of the fetus is genetically determined or caused by environmental events not routinely considered pregnancy complications. | {
"pile_set_name": "PubMed Abstracts"
} |
Ovariectomy Modifies TH2, and TH17 Balance in BALB/C Allergic Mice.
Asthma is a chronic inflammation of the airways affecting over 300 million people worldwide. As in the autoimmune diseases, it is well described that women are the most affected by asthma. The higher number of women presenting this pathology suggests the involvement of female sex hormones in the construction of the allergic immune response. Female Balb / c mice were used for the experiments. Thirty-eight animals were separated into four groups: OVX-Ova; Sham-Ova; OVX-Sal; Sham-Sal. Then animals underwent acute allergic induction protocol by Ovalbulmin (OVA). Ovariectomized animals showed greater number of leukocytes in bronchoalveolar lavage (BAL) and elevated white blood cells recruitment to the lung environment observed by histological analysis. There was a significant increase of eosinophils and mast cells in inflammatory sites at pulmonary tissue. The relative uterine and body weight were lower in ovariectomized animals and higher in Sham mice, respectively. Moreover, the lack of the sex hormones induced an increase in interleukin (IL)-4 and titers of immunoglobulin G1 (IgG1) antibodies. However, increased production of IL-17A was only observed in Sham animals. Altogether, data this study suggest that ovariectomy induces the formation of a stronger Th2 response in allergic animal. However, the immune processes involved in the allergic response in females currently remain unclear. | {
"pile_set_name": "PubMed Abstracts"
} |
Progressive loss of perivascular nerves adjacent to colorectal cancer.
The perivascular innervation of arterioles in colorectal cancer and adjacent submucosa was investigated. Neurotransmitter markers, neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), substance P (SP), calcitonin gene-related peptide (CGRP) and tyrosine hydroxylase (TH), were studied and immunoreactivity was compared with that of control normal tissue. There was absence of perivascular nerves within tumours and loss of perivascular innervation in the submucosa adjacent to the tumour. The pattern of loss varied for different transmitters. The loss was progressively greater with advancing tumour stage for NPY (controls 95%, Dukes' A 68%, Dukes>> B 13%, Dukes' C 6%) and VIP (50%, 23%, 20%, 17%). For TH there was extensive loss of innervation around tumours of all stages (69%, 5%, 7%, 0%). SP immunoreactive peri-arteriolar nerves were similar in control tissue (39%) and tissue adjacent to Dukes' A tumours (40%) but diminished to 19% and 0% in tissue adjacent to Dukes' B and C tumours, respectively. In none of the tissues was CGRP immunoreactivity above 4%. The mean distance over which there was reduced NPY immunoreactivity from the tumour edge was 2.43 mm for Dukes' A/B tumours compared with 7.20 mm for Dukes' C tumours; for VIP immunoreactivity this distance was 5.22 mm for Dukes' A/B tumours and 5.52 mm for Dukes' C tumours. The progressive loss, both in terms of vascular nerve immunoreactivity and distance from the tumour edge with tumour grade, suggests that the tumour itself may influence neural integrity in perivascular plexuses, perhaps via the secretion of an inhibitory factor. | {
"pile_set_name": "PubMed Abstracts"
} |
Banding patterns and chromosomal evolution in five species of neotropical Teiinae lizards (Squamata: Teiidae).
Karyotypes of five species of South American teiid lizards from subfamily Teiinae: Ameiva ameiva, Kentropyx calcarata, K. paulensis, K. vanzoi (2n = 50, all acrocentric), and Cnemidophorus ocellifer (2n = 50, all biarmed), are herein described and compared on the basis of conventional and silver staining, and CBG and RBG banding patterns. Meiotic data are also included. Karyotypes of K. paulensis, K. vanzoi, and C. ocellifer are reported here for the first time. Inter-generic variability in Ag-NORs location was detected with NORs occurring at the end of long arm of pair 1 in K. calcarata, K. paulensis, and K. vanzoi; pair 5 in C. ocellifer and pair 7 in A. ameiva. The location of NORs, along with the karyological differences between A. ameiva and the Central American species (A. auberi), corroboretes the molecular-based hypothesis that the genus Ameiva is paraphyletic. Inter-populational heteromorphism in Ag-NORs size was detected between populations of C. ocellifer. RBG and CBG banding data demonstrated that the biarmed condition of the C. ocellifer chromosomes is due to multiple pericentric inversion events instead of addition of constitutive heterochromatin. Differential-staining techniques used here revealed valuable information about Teiinae karyotypic diversity and made it possible to compare these species, contributing to both the better comprehension of their chromosomal evolution and issues on taxa systematics. | {
"pile_set_name": "PubMed Abstracts"
} |
Use of Tissue Electric and Ultrasound Characteristics to Predict and Prevent Steam-Generated Cavitation During High-Power Radiofrequency Ablation.
Given a paucity of data, the aim of this study was to define predictors of steam pops (SPs) during open-irrigated radiofrequency ablation (RFA). SPs during RFA can lead to dire consequences, including perforation and stroke. In an ex vivo bovine myocardium model, open-irrigated RFA was applied at 50 W for 60 s; intracardiac echocardiographic images for RFA with and without SPs was compared. Using an in vivo porcine model, open-irrigated RFA was applied at 50 W for 60 s, and RFA parameters of SPs were analyzed. A retrospective analysis was performed of recorded SPs during clinical ablation procedures over a 1-year period. For RFA SPs, there was 32% greater intracardiac echocardiographic tissue echogenicity than for RFA without SPs (p < 0.001). In addition, RFA SPs had more rapid increases of tissue echogenicity, particularly in the last 5 s before SPs. Compared with RFA without SPs, RFA SPs had larger impedance reductions (33.0 ± 16.0 Ω vs. 23.0 ± 10.8 Ω; p = 0.032). SPs were also associated with more rapid initial impedance reduction (1.40 Ω/s vs. 0.38 Ω/s for RFA without SPs; p = 0.001). Clinical SPs during ablation procedures had a significantly faster impedance reduction during the first 5 s of ablation compared with matched control ablations (15.7 ± 6.7 Ω vs. 8.1 ± 4.7 Ω; p < 0.0001). Certain echocardiographic and biophysical parameters during open-irrigated RFA are associated with increased SP risks. These include greater tissue echogenicity, larger total impedance reduction, rapid rate of initial impedance reduction, and rapid increase in tissue echogenicity. | {
"pile_set_name": "PubMed Abstracts"
} |
Incidence and persistence of silver nanoparticles throughout the wastewater treatment process.
While the predicted or observed concentrations of Ag NPs in wastewater treatment plants (WWTPs) have ranged from μg/L to ng/L, there is still uncertainty with regards to the realistic concentration range of Ag NPs in WWTPs. In addition, the persistence, removal, and size of Ag NPs throughout WWTP process is also not well investigated, particularly in real operating conditions. In this study, the incidence and persistence of Ag NPs in the wastewater process were studied by using single particle inductively coupled plasma mass spectrometry (sp-ICP-MS). The incidence of Ag NPs was determined in samples collected at the influent and effluent of the conventional process, as well as reclaimed and backwash waters of the ultrafiltration (UF) system in a WWTP (Santa Barbara, CA), showing a concentration of 13.5, 3.2, 0.5 and 9.8 ng/L, respectively, with relative standard deviations (RSDs) < 5%. Total Ag concentration (Ag NP and Ag+) ranged from 40 to 70 ng/L, in line with lower predicted values. Most of the Ag NPs detected were below 100 nm, with a few above 100 nm in the conventional effluent. Biological and physical processes in the secondary treatment removed 76.3% of the colloidal Ag fraction, while with the tertiary treatment (UF) the WWTP achieved a removal of 96.3% of the colloidal fraction. Persistence of Ag NPs in various water matrixes, including a synthetic wastewater (SWW), was determined by spiking 300 ng/L of Ag NPs (40 nm) and monitoring the concentrations and size change for 15 days. The persistence of Ag NPs in suspension was Influent > Effluent > Reclaimed > SWW. Partial dissolution of NPs in all waters was observed from time 0 h. Although the current concentrations in the outlet flows from WWTP (effluent and reclaimed waters) were low, the presence of small and stable Ag NPs may raise ecotoxicological concerns via bioaccumulation. | {
"pile_set_name": "PubMed Abstracts"
} |
Dithieno[3,2-b:2',3'-d]arsole-containing conjugated polymers in organic photovoltaic devices.
Arsole-derived conjugated polymers are a relatively new class of materials in the field of organic electronics. Herein, we report the synthesis of two new donor polymers containing fused dithieno[3,2-b:2',3'-d]arsole units and report their application in bulk heterojunction solar cells for the first time. Devices based upon blends with PC71BM display high open circuit voltages around 0.9 V and demonstrate power conversion efficiencies around 4%. | {
"pile_set_name": "PubMed Abstracts"
} |
An enzymatic pathway for the biosynthesis of the formylhydroxyornithine required for rhodochelin iron coordination.
Rhodochelin, a mixed catecholate-hydroxamate type siderophore isolated from Rhodococcus jostii RHA1, holds two L-δ-N-formyl-δ-N-hydroxyornithine (L-fhOrn) moieties essential for proper iron coordination. Previously, bioinformatic and genetic analysis proposed rmo and rft as the genes required for the tailoring of the L-ornithine (L-Orn) precursor [Bosello, M. (2011) J. Am. Chem. Soc.133, 4587-4595]. In order to investigate if both Rmo and Rft constitute a pathway for L-fhOrn biosynthesis, the enzymes were heterologously produced and assayed in vitro. In the presence of molecular oxygen, NADPH and FAD, Rmo monooxygenase was able to convert L-Orn into L-δ-N-hydroxyornithine (L-hOrn). As confirmed in a coupled reaction assay, this hydroxylated intermediate serves as a substrate for the subsequent N(10)-formyl-tetrahydrofolate-dependent (N(10)-fH(4)F) Rtf-catalyzed formylation reaction, establishing a route for the L-fhOrn biosynthesis, prior to its incorporation by the NRPS assembly line. It is of particular interest that a major improvement to this study has been reached with the use of an alternative approach to the chemoenzymatic FolD-dependent N(10)-fH(4)F conversion, also rescuing the previously inactive CchA, the Rft-homologue in coelichelin assembly line [Buchenau, B. (2004) Arch. Microbiol.182, 313-325; Pohlmann, V. (2008) Org. Biomol. Chem.6, 1843-1848]. | {
"pile_set_name": "PubMed Abstracts"
} |
Forensic psychiatric nursing: a literature review and thematic analysis of role tensions.
This literature review was undertaken to explore the emergent issues relating to the difficulties encountered in forensic psychiatric nursing. The rationale for the study revolved around the paucity of research undertaken to identify the constituent parts of this professional practice. The aims included both a thematic analysis of the literature and the construction of a theoretical framework to guide further research. The method was a snowballing collection of literature and a computerized database search. The results were the identification of a series of major issues, which were broadly categorized as negative and positive views, security vs. therapy, management of violence, therapeutic efficacy, training and cultural formation. From this the six binary oppositions, or domains of practice, emerged as a theoretical framework to develop further research. These were medical vs. lay knowledge, transference vs. counter-transference, win vs. lose, success vs. failure, use vs. abuse, and confidence vs. fear. Further research is currently underway. | {
"pile_set_name": "PubMed Abstracts"
} |
Improve Markets, Not Government Controls, for Real Health Reform.
Proposals to replace the existing mix of public and private health financing with a fully nationalized government system ("Medicare for All") fail to address fundamental problems of high cost, overutilization, and inefficiency. Those proposals are a reaction to the Affordable Care Act, which provided new insurance subsidies but did little to solve the cost problem. Stabilizing the individual insurance market is not the goal. Reform should focus on making the entire insurance market and the health delivery system more efficient and more equitable by promoting consumer choice, market competition, private initiative, and state experimentation. | {
"pile_set_name": "PubMed Abstracts"
} |
Real-time assessment of acute myocardial ischaemia by an intra-thoracic 6-lead ECG: evaluation of a new diagnostic option in the implantable defibrillator.
In the presence of coronary artery disease, implantable cardioverter-defibrillators (ICD) are used effectively for treating life-threatening tachyarrhythmias. Continuous monitoring of myocardial ischaemia would provide a new diagnostic option in future ICD generations. In 22 selected patients undergoing coronary angioplasty, percutaneous transluminal coronary angioplasty (PTCA), three electrodes, similar to those used in the ICD, were inserted aiming to create six intra-thoracic ECG (IT-ECG) leads according to Einthoven and Goldberger. In total, 27 PTCA were conducted. The diagnostic efficacy for ischaemia assessment was compared with the surface ECG. The IT-ECG proved to be more sensitive than conventional ECG in early and overall ischaemia assessment. At 30 s of coronary artery occlusion, ischaemic ST-segment alterations (> or =0.25 mV) were present in the IT-ECG 2.3 times more often (23 vs. 10/27 PTCA attempts, P<0.01) and at 90 s 1.4 times more often compared with conventional ECG leads (18 vs. 26/27, P<0.05). Intra-thoracic Einthoven 2 (SVC+RVA vs. ICD-housing) and Goldberger 3 (SVC+ICD-housing vs. RVA) had the highest sensitivity (88/85%). Using > or =4 IT-ECG, ischaemia monitoring was independent of severity and site of origin. IT-ECG signals showed double ST-T signal amplitude (4.19+/-0.6 vs. 2.15+/-0.3 mV, ratio: 1.95, P<0.01) at a QRS/ST amplitude ratio similar in the two ECG techniques. This study provides strong evidence that the ICD-based IT 6-lead ECG would provide a new and efficient means of assessing a patient's daily ischaemic burden. | {
"pile_set_name": "PubMed Abstracts"
} |
Functional reactivity of oxanine: its biological meanings and biotechnological applications.
Oxanine (Oxa), generated as one of the major products from guanine by nitrosative oxidation, has been focused as a mutagenic lesion. Here, Oxa was explored in terms of its unique property to react with - NH2 or -SH group since Oxa possesses O-acylisourea conformation in the base-ring structure. In particular, Oxa has been characterized in terms of its formation and mechanism of DNA-protein cross-link (DPC). In addition, Oxa was testified as a new carboxy-linker for activation-free covalent bonding with NH2-molecules, which can be usefully employed for the design of biotechnological or nano/biotechnological systems. | {
"pile_set_name": "PubMed Abstracts"
} |
Adult granulosa cell tumor of the ovary with foci of hepatic cell differentiation: a report of four cases and comparison with two cases of granulosa cell tumor with Leydig cells.
We report four ovarian granulosa cell tumors of the adult type containing small foci of hepatic cell differentiation. The patients ranged in age from 35 to 54 years and had unilateral adnexal masses. The smallest tumor was 4.0 cm in diameter and the largest, 11.0 cm in diameter. Three tumors were solid and cystic, and one was cystic. Microscopic examination showed typical patterns of adult granulosa cell tumor, with the additional finding of scattered islands of large cells with abundant eosinophilic, slightly granular cytoplasm and central round nuclei containing single prominent nucleoli. Bile pigment was detected in canaliculi between some of the large cells in three tumors. The hepatic cells were positive immunohistochemically for cytokeratin (CAM 5.2) and epithelial membrane antigen in two cases and alpha-fetoprotein in one of two cases. Carcinoembryonic antigen was stained in a canalicular pattern in two cases. Staining for vimentin and alpha-inhibin was negative. Liver cells in granulosa cell tumors must be differentiated from Leydig cells, which are found very rarely in granulosa cell tumors, and luteinized stromal and granulosa cells, which are present more commonly in these tumors; all three of the latter cell types are positive for alpha-inhibin. | {
"pile_set_name": "PubMed Abstracts"
} |
The influence of gender, social circumstances and smoking on survival: the Renfrew and Paisley study.
The present study aimed to compare survival to age 75 between men and women, by social circumstances and smoking behaviour. A 20 year follow up was carried out of a large representative cohort of Scottish men and women in the Renfrew and Paisley study, and was combined with Scottish mortality statistics. 6831 men and 7993 women aged 45-64 y at time of examination (between 1972 and 1976) were considered. Combining the estimates from the Renfrew and Paisley study with those from Scottish mortality statistics for men and women younger than 45 y of age, it was calculated that 28% of the male smokers and 44% of the male never smokers in disadvantaged social circumstances will have survived to age 75 y, compared with 46% and 56% of the female smokers and never smokers respectively. In more privileged social circumstances, 41% of the male smokers and 62% of the male never smokers will have survived to age 75 y, compared with 56% and 70% of the female smokers and never smokers respectively. The difference between male smokers in low social classes and female never smokers in high social classes is 42% in absolute terms (28% vs 70%), which gives an indication of the combined influence of gender, social circumstances and smoking on survival. These results show that gender, social circumstances and smoking are important determinants of mortality which have led to substantial differences in survival. The influence of additional factors related to mortality could usefully be compared to these to put their effects into perspective. | {
"pile_set_name": "PubMed Abstracts"
} |
Viremia copy-years as a predictive marker of all-cause mortality in HIV-1-infected patients initiating a protease inhibitor-containing antiretroviral treatment.
Viremia copy-years (VCY) has been reported as a short-term predictor of mortality. We evaluated the association of this parameter with 10-year outcome within the APROCO-COPILOTE cohort. Prospective data from 1281 HIV-1-infected patients who started a first protease inhibitor-containing regimen in 1997-1999 were analyzed. Patients with baseline plasma viral load (pVL) > 500 copies per milliliter and at least 2 pVL measures from the eighth month of follow-up were selected. VCY was calculated individually over the follow-up as the area under the pVL curve. Multivariate Cox models analyzed the relation between all-cause mortality and the following variables: age, sex, geographical origin, transmission group, HIV infection duration, ART-naive, pVL at baseline, time-dependent CD4 count, and VCY. Nine hundred seventy-nine patients were followed up for a median of 10 years (interquartile range: 5-11.5). At baseline, median (interquartile range) values for duration of HIV infection, pVL, and CD4 cell count were 43 (4-95) months, 4.6 (3.9-5.2) log10 copies per milliliter, and 278 (125-416) cells per cubic millimeter, respectively. At censoring date, 77 patients (8%) had died. VCY >1.4 log10 copies × yrs/mL was an independent predictor of death (hazard ratio: 2.0; 95% confidence interval: 1.2 to 3.5), which was no longer the case after adjustment for the latest pVL value [risk ratio (RR): 1.2 for 1 additional log10 copies per milliliter; 95% confidence interval: 1.1 to 1.4]. VCY was associated with mortality in HIV-infected patients under combined antiretroviral therapy but did not overweigh the predictive value of the latest pVL. VCY might be more useful as a marker of persistent viral replication than for routine clinical care. | {
"pile_set_name": "PubMed Abstracts"
} |
[Evaluation of a E-test method to detect bactericidy of beta lactam-aminoglycoside associations against Pseudomonas aeruginosa isolates from cystic fibrosis].
Pulmonary infectious exacerbations with Pseudomonas aeruginosa are the major problem for patients with cystic fibrosis. Emergence of multi-resistant mucoid strains leads to complicate the choice of antibiotherapy. Therefore, synergic and bactericidal treatment must be used. Then, it is interesting to estimate the bactericidal activity of antibiotics associations in order to optimise the treatment. The aim of this work is to describe a new method of bactericidal antibiotics combinations by superimposing 2 E-test strips and to compare results with those obtained with a broth bactericidal method chosen as reference method. Twenty strains of P. aeruginosa (13 mucoïd and 7 non mucoïd) were selected from expectorants of cystic fibrosis children. Four antibiotics combinations were tested (ceftazidime/tobramycine, cefepime/tobramycine, ceftazidime/amikacine, cefepime/amikacine). Two antibiotics combinations by superimposing E-test strips techniques were used: maximal concentration on maximal concentration (C(max)/C(max)) and minimal inhibitory concentration on minimal inhibitory concentration (MIC/MIC). The comparison of results between killing curves and superposition of E-test strips (C(max)/C(max)) show 88% agreements, 4% major discrepancies specially with mucoid strains and 8% minor discrepancies. The Cmax/Cmax method seems to give better results than MIC/MIC method. The superposition of E-test strips method is an attractive method: it is rapid, easy to use and well correlated to broth bactericidal method. | {
"pile_set_name": "PubMed Abstracts"
} |
[Search for microorganisms among collectable bacterial strains capable of transforming nucleosides into virazole].
The ability of bacterial cultures to transform nucleosides to virazole, a riboside with antiviral activity, was studied. Qualitative and quantitative methods for estimation of the microbial activity in the biotransformation reaction were designed. A qualitative rapid method for analysis of a large number of cultures was developed. Thirty nine collection strains were tested for their capacity to bioconvert nucleosides to virazole. Intact cells grown in a liquid medium were used as a source of purine nucleoside phosphorylase. Purine nucleosides such as adenosine, inosine, guanosine and 30-percent ribose solution resulting from the riboxin hydrolysis were tested as the ribose donors. The best results were obtained with the ribose solution. No distinct correlation between the genus of the microorganisms and their capacity for bioconversion of certain substrates was observed. Several cultures which showed stable and high results with respect to all the tested substrates were detected. | {
"pile_set_name": "PubMed Abstracts"
} |
Mind-mapped care plans: integrating an innovative educational tool as an alternative to traditional care plans.
Teaching nursing students how to think critically when planning patient care is vital to their professional success. Traditionally, the nursing care plan has been used to apply steps of the nursing process in planning patient care. However, nursing has evolved into a more complex profession that requires expanded ways of thinking and reasoning beyond the linear methods used in the past. Mind-mapped care plans provide an alternative method of teaching holistic, patient-centered care. This article describes the process used to integrate the mind-mapped care plan as an innovative educational tool, as well as formative and summative outcomes of its use. | {
"pile_set_name": "PubMed Abstracts"
} |
A quantitative assessment of femoral head activity using 99Tcm -polyphosphate and a computer data collection system.
Abnormal femoral head activity in Legg-Calve-Perthes' disease has been measured using 99Tcm -polyphosphate and a gamma camera/computer data collection system. A reference point on the data matrix, which is unaffected by the diease, is used for deriving comparative uptake ratios in each femoral head. The reference point remains unaltered after surgical procedures or short intervals between follow-up studies. Early abnormality can be measured in both unilateral and bilateral femoral head pathology. | {
"pile_set_name": "PubMed Abstracts"
} |
Phosphorylation of placental membrane proteins by a calcium- and phospholipid-dependent protein kinase.
The 30 000 g precipitate of homogenized rat placenta was incubated with 32P-adenosine triphosphate (ATP); several endogenous proteins were specifically phosphorylated in the presence of 0.5 mM calcium and phosphatidylserine (105K protein at mid pregnancy, and 78K protein at the latter part of pregnancy). The calcium- and phospholipid-dependent protein kinase activity in the 30 000 g precipitate was six times greater than the activity in the supernatant fraction. The total protein kinase C activity in the precipitate was considerably greater at the end of pregnancy than it was at mid pregnancy. Diethylaminoethyl cellulose-purified membrane-bound protein kinase C was slightly inhibited by inhibitors of lipoxygenase, NDGA or ETYA, but not by SHAM or BW755C. Haemin and polylysine strongly inhibited this activity. | {
"pile_set_name": "PubMed Abstracts"
} |
Adjuvant topiramate administration: a pharmacologic strategy for addressing NMDA receptor hypofunction in schizophrenia.
N-methyl-d-aspartate receptor hypofunction (NRH) and its downstream consequences, especially excitotoxicity, may explain the progressive psychosocial deterioration and ventriculomegaly observed in at least some patients with schizophrenia. Topiramate has several properties that address downstream consequences of NRH. In this open-label investigation, the authors examined the salutary therapeutic effects of adjuvant topiramate in 12 patients with schizophrenia and schizoaffective disorder. Patients were selected on the basis of the presence of negative symptoms. An optimal dose of topiramate was determined for each patient during a slow 4-week titration process. Patients were maintained on topiramate and their stable antipsychotic medications for 8 weeks, after which topiramate was tapered and discontinued. Patients were followed for an additional 4 weeks on their stable antipsychotic medications. Clinical measures of efficacy (eg, Positive and Negative Syndrome Scale), cognitive measures (eg, verbal fluency, memory), and safety measures (eg, postural sway) were assessed throughout this study. Topiramate administration (average dose, 110.42 mg/day) decreased total scores on the Positive and Negative Syndrome Scale. Topiramate was also associated with a selective and reversible worsening of verbal fluency performance. These results encourage further testing of topiramate and kainate/alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor antagonists in schizophrenia patients and support the heuristic model of NRH. | {
"pile_set_name": "PubMed Abstracts"
} |
Neurites from PC12 cells are connected to each other by synapse-like structures.
PC12 cells have been used as a model of sympathetic neurons. Nerve growth factor (NGF), basic fibroblast growth factor (bFGF), and cAMP induce neurite outgrowth from PC12 cells. cAMP induced a greater number of neurites than did NGF. In particular, we attempted to elucidate whether PC12 cell neurites, induced by several factors including NGF, bFGF, and cAMP, form synapses, and whether each neurite has presynaptic and postsynaptic properties. Using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), we observed that neurites are connected to each other. The connected regions presented dense core vesicles and a clathrin-coated membrane invagination. In addition, typical maker proteins for axon and dendrite were identified by an immuno-staining method. Tau-1, an axonal marker in neurons, was localized at a high concentration in the terminal tips of neurites from PC12 cells, which were connected to neurite processes containing MAP-2, a dendritic marker in neurons. Furthermore, neurites containing SV2 and synaptotagmin, markers of synaptic vesicles, were in contact with neurites harboring drebrin, a marker of the postsynaptic membrane, suggesting that neurites from PC12 cells induced by NGF, bFGF, and cAMP may form synapse-like structures. Tat-C3 toxin, a Rho inhibitor, augmented neurite outgrowth induced by NGF, bFGF, and cAMP. Tat-C3 toxin together with neurotrophins also exhibited synapse-like structures between neurites. However, it remains to be studied whether RhoA inhibition plays a role in the formation of synapse-like structures in PC12 cells. | {
"pile_set_name": "PubMed Abstracts"
} |
Effect of nitrate and nitrite on Listeria and selected spoilage bacteria inoculated in dry-cured ham.
The effect of nitrate and the combination of nitrate/nitrite on Listeria innocua (as surrogate of Listeria monocytogenes). And two selected spoilage microorganisms (Proteus vulgaris and Serratia liquefaciens) was studied in dry-cured ham. Hams were manufactured with different concentrations of curing agents: KNO3 (600 and 150mg/kg) alone or in combination with NaNO2 (600 and 150mg/kg). The addition of 500mg/kg of sodium ascorbate was also evaluated in a batch with 600mg/kg of nitrate and nitrite. The target microorganisms were inoculated by injection in semimembranosus, biceps femoris and in the shank, prior to curing. P. vulgaris and S. liquefaciens were controlled by temperature and aw, respectively, and no effect of nitrate/nitrite was observed. The presence of nitrite in the curing mix reduced L. innocua in semimembranosus, which population was 1.5logcfu/g lower at the end of resting (p<0.05), while at the end of the process it was more frequently detected in the no- and low-nitrite added hams. None of the treatments was able to control Listeria in deeper areas of ham. The addition of sodium ascorbate to the curing mix containing the highest amount of nitrate and nitrite did not show any effect on the microorganisms studied. | {
"pile_set_name": "PubMed Abstracts"
} |
[Analysis of inconstancy of epidemic outbreaks within the dynamics of seasonal rise in mortality].
The possible cause of inconstancy appear against a background rhythmical repeated the seasonal raising of morbidity epidemic outbreak is studied by mathematical modeling. Results of the research are applied to influenza epidemics outbreaks against a background of seasonal raising of respiratory morbidity. Mechanism of outgrowing of seasonal raising to epidemic outbreak is explained as a change of the stable equilibrium by temporary unstable one. | {
"pile_set_name": "PubMed Abstracts"
} |
An organotypic coculture model supporting proliferation and differentiation of medullary thymic epithelial cells and promiscuous gene expression.
Understanding intrathymic T cell differentiation has been greatly aided by the development of various reductionist in vitro models that mimic certain steps/microenvironments of this complex process. Most models focused on the faithful in vitro restoration of T cell differentiation and selection. In contrast, suitable in vitro models emulating the developmental pathways of the two major thymic epithelial cell lineages--cortical thymic epithelial cells and medullary thymic epithelial cells (mTECs)--are yet to be developed. In this regard, lack of an in vitro model mimicking the developmental biology of the mTEC lineage has hampered the molecular analysis of the so-called "promiscuous expression" of tissue-restricted genes, a key property of terminally differentiated mTECs. Based on the close biological relationship between the skin and thymus epithelial cell compartments, we adapted a three-dimensional organotypic coculture model, originally developed to provide a bona fide in vitro dermal equivalent, for the culture of isolated mTECs. This three-dimensional model preserves key features of mTECs: proliferation and terminal differentiation of CD80(lo), Aire(-) mTECs into CD80(hi), Aire(+) mTECs; responsiveness to RANKL; and sustained expression of FoxN1, Aire, and tissue-restricted genes in CD80(hi) mTECs. This in vitro culture model should facilitate the identification of molecular components and pathways involved in mTEC differentiation in general and in promiscuous gene expression in particular. | {
"pile_set_name": "PubMed Abstracts"
} |
Clinical significance of p53 functional loss in squamous cell carcinoma of the oropharynx.
We examined the frequency of p53 mutations in 38 oropharyngeal squamous cell carcinomas (SCC), using both a yeast functional assay and a conventional immunohistochemical staining method (IHC) to detect p53 mutations. We also explored the clinical importance of p53 mutations in oropharyngeal SCC. An accumulation of p53 protein was detected in 17 of the 38 (45%) tumors by IHC, whereas the yeast-based assay detected 6 additional p53 mutations, for a total of 23 tumors (61%) with p53 mutations. The cDNA sequencing analysis revealed that the 6 mutations undetected by IHC consisted of 3 frameshift, 1 nonsense and 2 missense mutations. Thus, the yeast functional assay was more sensitive than conventional IHC for detecting p53 mutations. Subsequently, the relationship between p53 mutations and the clinico-pathological parameters in oropharyngeal SCC was evaluated using the results of the functional assay. Mutation of p53 was not associated with the patient age, sex, tumor stage or degree of tumor cell differentiation. Interestingly, heavy drinking had a significant positive correlation with the p53 mutation, but heavy smoking did not, suggesting that prolonged exposure to alcohol is more related to p53 mutation in oropharyngeal SCC than to tobacco consumption. Radiation sensitivity was examined by comparing tumor size on magnetic resonance images before and after completion of therapy with 45 Gy radiation, in the 18 cases of T2 oropharyngeal SCC that were initially treated by radiotherapy. The results showed that tumors with wild-type p53 decreased in size significantly compared to those with mutant p53. In 33 patients treated with curative intent, the overall survival after the completion of therapy was better in patients with a wild-type p53 tumor than in patients with a mutant p53 tumor. We conclude that p53 mutation is associated with radiation resistance and a decreased probability of survival in oropharyngeal SCC. | {
"pile_set_name": "PubMed Abstracts"
} |
The Chemistry and Biology of Alkannin, Shikonin, and Related Naphthazarin Natural Products.
Wound healing properties of plant extracts that contain the naphthoquinone natural products alkannin (1) and shikonin (2) have been known for many centuries. More recently, the biological properties of 1, 2, and related derivatives have been demonstrated experimentally, and their production both by cell cultures and chemical synthesis has been studied extensively. | {
"pile_set_name": "PubMed Abstracts"
} |
[Molecular pharmacology of opioid receptors].
We cloned kappa and mu opioid receptor cDNAs. Using these cDNAs, first, we examined the molecular mechanism for the subtype selectivity of opioid ligands, especially a mu-selective ligand DAMGO. Binding experiments using various chimera and mutated receptors revealed that DAMGO discriminates between mu and delta receptors by recognizing the difference in only one amino acid residue, that is, N(127) in mu and K(108) in delta, at the first extracellular loop, and that it distinguishes between mu and kappa receptors by the difference in four amino acid residues at the third extracellular loop. Second, we established the cell lines expressing the cloned mu, delta, or kappa receptor and elucidated the pharmacological properties, that is, binding affinity and agonistic activity of several opioid agonists. Third, distribution of the mRNAs for mu, delta, and kappa receptors in the brain, spinal cord, and DRG was examined by in situ hybridization histochemistry (ISHH). Double ISHH demonstrated that most of the substance P-producing DRG neurons express the micro receptor. Recently, we are interested in the emotional aspect of pain and its regulation by opioids. Behavioral and microdialysis studies showed that sustained pain evoked by the intraplanter injection of formalin induced conditioned place aversion through the increment of glutamate release followed by the activation of NMDA receptors in the basolateral nucleus of amygdala (BLA). Intra-BLA injection of morphine suppressed the place aversion by inhibiting the glutamate release. | {
"pile_set_name": "PubMed Abstracts"
} |
Further evidence for a cell surface proteinase essential to the growth of cultured fibroblasts.
Specific antibodies and protein proteinase inhibitors will inhibit cell-surface proteinase activity on human fibroblasts and cause a concomitant inhibition of DNA synthesis and of cell multiplication. An insolubilized proteinase inhibitor also inhibits cell multiplication. The same reagents partially inhibit the multiplication of mouse L cells, both in monolayer and suspension culture, and inhibit the mitogenic effect of epidermal growth factor (EGF) on both types of cell. | {
"pile_set_name": "PubMed Abstracts"
} |
Nonstoichiometric perovskite CaMnO(3-δ) for oxygen electrocatalysis with high activity.
Perovskite oxides offer efficient and cheap electrocatalysts for both oxygen reduction reactions and oxygen evolution reactions (ORR/OER) in diverse oxygen-based electrochemical technologies. In this study, we report a facile strategy to enhance the electrocatalytic activity of CaMnO3 by introducing oxygen defects. The nonstoichiometric CaMnO(3-δ) (0 < δ ≤ 0.5) was prepared through thermal reduction of pristine perovskite microspheres and nanoparticles, which were synthesized from thermal-decomposition of carbonate precursors and the Pechini route, respectively. The as-prepared samples were analyzed by chemical titration, structural refinement, thermogravimetric analysis, and energy spectrometry. In 0.1 M KOH aqueous solution, the nonstoichiometric CaMnO(3-δ) with δ near 0.25 and an average Mn valence close to 3.5 exhibited the highest ORR activity (36.7 A g(-1) at 0.70 V vs RHE, with onset potential of 0.96 V), which is comparable to that of benchmark Pt/C. Density functional theory (DFT) studies and electrical conductivity measurement revealed that the enhanced ORR kinetics is due to facilitated oxygen activation and improved electrical properties. Besides high activity, the nonstoichiometric perovskite oxides showed respectable catalytic stability. Furthermore, the moderate oxygen-defective CaMnO(3-δ) (δ ≈ 0.25) favored the OER because of the improved electrical conductivity. This study makes nonstoichiometric CaMnO(3-δ) a promising active, inexpensive bifunctional catalytic material for reversible ORR and OER. | {
"pile_set_name": "PubMed Abstracts"
} |
Role of nitric oxide in beta3-adrenoceptor activation on basal tone of internal anal sphincter.
Effects of activation of beta3-adrenoceptor (beta3-AR) have not been determined in the spontaneously tonic smooth muscle of the internal anal sphincter (IAS). The effects of disodium (R,R)-5-[2-[2-3-chlorophenyl)-2-hydroxyethyl]-amino]propyl]-1,3-benzodioxole-2,2-dicarboxylate (CL 316243), a selective beta3-AR agonist, on the basal smooth muscle tone and direct release of nitric oxide (NO) by circular smooth muscle strips of the opossum IAS were determined. We also examined the presence of endothelial nitric oxide synthase (eNOS) protein by Western blot studies. CL 316243 produced a concentration-dependent relaxation of the smooth muscle that remained unmodified by different neurohumoral antagonists. The smooth muscle relaxation by CL 316243 was selectively antagonized by L 748337, a beta3-AR antagonist. Such relaxation was several times longer than by isoproterenol. The effect of CL 316243 was significantly attenuated by a nonselective NOS inhibitor N(omega)-nitro-l-arginine (l-NNA) and by putative inhibitor of eNOS l-N5-(1-iminoethyl)-ornithine dihydrochloride (l-NIO). Inhibitors of iNOS [N-(3-aminomethyl)benzyl acetamide 2HCl] and nNOS [1-[2-(trifluoromethylphenyl)imidazole]] had no effect on this relaxation. Relaxation of the IAS smooth muscle induced by CL 316243 was accompanied by an increased release of NO; this was attenuated by l-NNA and l-NIO. In addition, Western blot studies revealed the presence of eNOS in the circular smooth muscle of the IAS. These data demonstrate potent and protracted IAS smooth muscle relaxation by beta3-AR activation, which is partly transduced via NOS, possibly smooth muscle eNOS. Multiple signal-transduction pathways including NOS activation may explain the characteristic IAS relaxation by beta3-AR activation. The studies may have therapeutic implications in anorectal motility disorders. | {
"pile_set_name": "PubMed Abstracts"
} |
Rouxiella chamberiensis gen. nov., sp. nov., a member of the family Enterobacteriaceae isolated from parenteral nutrition bags.
Parenteral nutrition bags for newborns were found contaminated by a previously undescribed member of the family Enterobacteriaceae. The six isolates studied by rrs gene (encoding 16S rRNA) sequence analysis and multi-locus sequence analysis (MLSA) formed a discrete branch close to the genera Ewingella, Rahnella, Yersinia,Hafnia and Serratia. Phenotypically, the new taxon was distinct from these five genera. The new taxon gave positive results in Voges-Proskauer, Simmons citrate and o-nitrophenyl-β-galactoside hydrolysis tests; fermented d-glucose, d-mannitol, l-rhamnose, melibiose, l-arabinose and d-xylose; hydrolysed aesculin; and did not ferment maltose, trehalose, raffinose, d-sorbitol, sucrose or cellobiose. Tests for motility, gas production, urease, gelatinase and nitrate reduction were also negative. All isolates failed to grow at 37 °C. The DNA G+C content of strain 130333T was 53 mol%. On the basis of data obtained in this study, the six isolates represent a novel species of a new genus in the family Enterobacteriaceae, named Rouxiella chamberiensis gen. nov., sp. nov. The type strain of the type species is 130333T ( = CIP 110714T = DSM 28324T). | {
"pile_set_name": "PubMed Abstracts"
} |
[Manifestation of adult celiac disease during the puerperium].
The coeliac disease is a T cell mediated autoimmune enteropathy, presents in genetically susceptible person exposed to gluten. It can manifest in any age group but it is becoming more commonly diagnosed in adulthood. Very rarely it manifests during pregnancy or after childbirth, possibly due to hormonal and immunological changes. In authors' case a young female developed severe diarrhoea resulting in malabsorption following both of her pregnancies. On the first presentation the gluten sensitive enteropathy was not diagnosed despite detailed gastroenterological and endocrine workup. Following her first pregnancy she remained free of symptoms for years on a normal diet. After the birth of her second child her symptoms flared up and she was admitted to authors' department. The diagnosis of coeliac disease was confirmed by the histological finding from a small bowel biopsy. The coeliac specific serologic markers were also positive (antibodies to gliadin, endomysium and tissue transglutaminase). Significant improvement was achieved with supportive therapy and gluten-free diet. Despite the fact that authors' patient's symptoms were transient, the diagnosis of latent coeliac disease seems to be evident. Lifelong gluten-free diet is mandatory to prevent the late complications. | {
"pile_set_name": "PubMed Abstracts"
} |
Posttraumatic stress disorder and interpersonal functioning in Vietnam War veterans: a mediational model.
This study examines the association between posttraumatic stress disorder (PTSD) and interpersonal functioning in a New Zealand community sample of 756 Vietnam War veterans. The results support previous research findings showing that PTSD adversely affects veterans' interpersonal relationships, family functioning, and marital/dyadic adjustment and show that the effects of PTSD on family functioning and dyadic adjustment are mediated by severity of interpersonal problems. It is suggested that higher levels of PTSD affect the ability of veterans to initiate and maintain interpersonal relationships and that these interpersonal problems are evident in poorer levels of family functioning and poorer dyadic adjustment. | {
"pile_set_name": "PubMed Abstracts"
} |
Bioisosteric phentolamine analogs as potent alpha-adrenergic antagonists.
The synthesis and biological evaluation of a new series of bioisosteric phentolamine analogs are described. Replacement of the carbon next to the imidazoline ring of phentolamine with a nitrogen atom provides compounds (2, 3) that are about 1.6 times and 4.1 times more potent functionally than phentolamine on rat alpha1-adrenergic receptors, respectively. In receptor binding assays, the affinities of phentolamine and its bioisosteric analogs were determined on the human embryonic kidney (HEK) and Chinese Hamster ovary (CHO) cell lines expressing the human alpha1- and alpha2-AR subtypes, respectively. Analogs 2 and 3, both, displayed higher binding affinities at the alpha2- versus the alpha1-ARs, affinities being the least at the alpha1B-AR. Binding affinities of the methoxy ether analog 2 were greater than those of the phenolic analog 3 at all six alpha-AR subtypes. One of the nitrogen atoms in the imidazoline ring of phentolamine was replaced with an oxygen atom to give compounds 4 and 5, resulting in a 2-substituted oxazoline ring. The low functional antagonist activity on rat aorta, and binding potencies of these two compounds on human alpha1A- and alpha2A-AR subtypes indicate that a basic functional group is important for optimum binding to the alpha1- and alpha2A-adrenergic receptors. | {
"pile_set_name": "PubMed Abstracts"
} |
Application of microcalorimetry for recording basal metabolic and Na+, K+-ATPase activity in LLC-PK1 cells, a model for the renal tubular epithelial cell.
In the present study we have employed a microcalorimetric procedure to measure the heat generated by a porcine renal tubule cell line (LLC-PK1) and its Na+, K+-ATPase. Microplates with an area of 2.2 cm2 were found to be optimal in terms of producing sufficient heat and a steady-state power curve. We compared the rate of heat production by cells in suspension and on monolayers and found a much lower value in suspension, that is, 1.42+/-0.2 versus 2.54+/-0.19 microW/microg DNA. Ouabain, the specific Na+, K+-ATPase inhibitor, caused a reduction in this heat output. The maximal inhibition in cell suspensions was 40% and remained unchanged with as much as 100 microM ouabain, the highest concentration tested. With cells cultured on microplates, ouabain in the concentration interval 0.1-3 microM caused a 25% inhibition of heat output. With 25-100 microM ouabain, a 50% inhibition was observed and at higher concentrations, no further inhibition occurred. Furthermore, upon removal of ouabain, full recovery of the Na+, K+-ATPase was observed, a process that could easily be monitored by using cell monolayers cultured on microplates. | {
"pile_set_name": "PubMed Abstracts"
} |
Thrombogenicity of hydrophilic and nonhydrophilic microcatheters and guiding catheters.
To assess in a swine model the in vivo thrombogenicity of various microcatheters and guiding catheters as a function of catheter material, catheter coating, and duration of implantation. Microcatheters (Tracker 18 and Fastracker 18, Target Therapeutics, Fremont, Calif; Magic 1.8, Balt, Montmorency, France; and Transit, Cordis Endovascular Systems, Miami Lakes, Fla) were placed through 6F guiding catheters (Fasguide, Target Therapeutics, and Envoy, Cordis Endovascular Systems) into the common carotid arteries of swine for 30 minutes (short term), 90 minutes (medium term), and 35 days (long term). Guiding catheters were implanted for 5 hours. At the end of the implantation periods the catheters were retracted and fixed for scanning electron microscopy. The surface of the Fastracker microcatheter was devoid of debris after both short- and medium-term implantation. The Tracker microcatheter had minimal accumulation of cellular elements whereas the Transit microcatheter showed moderate accumulation of nondeformed red blood cells. Neither the Tracker nor the Transit microcatheter showed evidence of increasing debris accumulation after medium-term implantation as compared with short-term implantation. The Magic microcatheter was coated with gross thrombus after both short- and medium-term implantation. The Fasguide guiding catheter was nearly devoid of debris, while the Envoy guiding catheter had moderate thrombus formation. Long-term implantation of the Fastracker microcatheter was well tolerated whereas that of the Transit catheter resulted in vessel occlusion. Hydrophilic microcatheters and guiding catheters are less thrombogenic than their nonhydrophilic counterparts, but not all hydrophilic coatings are equally hypothrombogenic. Degree of thrombogenicity depends on catheter material rather than surface morphology. Medium-term implantation did not yield increasing thrombus formation relative to short-term implantation. | {
"pile_set_name": "PubMed Abstracts"
} |
Linear trapdoor or "white-eye" blowout fracture of the orbit: not restricted to children.
The management of orbital blowout fractures remains controversial, particularly in patients with a white-eye or trapdoor-type injury. We report our experience with 10 such cases (mean age 19.6 years, range 4-53) and show, unlike previous reports, that this pattern of injury is not restricted to children. Although most patients had a white eye (70%), the presence of subconjunctival haemorrhage and periorbital bruising did not exclude this injury, and the patients often (60%) had serious autonomic symptoms such as nausea and vomiting. A high index of suspicion and cross-sectional imaging is required to confirm the diagnosis. Early intervention (less than 7 days) seems to be associated with better outcome, but patients benefitted from intervention up to 41 days after injury. The mechanism underlying this pattern of injury and the rationale behind early intervention is also discussed. | {
"pile_set_name": "PubMed Abstracts"
} |
Stem cell biology and regenerative medicine for neonatal lung diseases.
Lung diseases remain one of the main causes of morbidity and mortality in neonates. Cell therapy and regenerative medicine have the potential to revolutionize the management of life-threatening and debilitating lung diseases that currently lack effective treatments. Over the past decade, the repair capabilities of stem/progenitor cells have been harnessed to prevent/rescue lung damage in experimental neonatal lung diseases. Mesenchymal stromal cells and amnion epithelial cells exert pleiotropic effects and represent ideal therapeutic cells for bronchopulmonary dysplasia, a multifactorial disease. Endothelial progenitor cells are optimally suited to promote lung vascular growth and attenuate pulmonary hypertension in infants with congenital diaphragmatic hernia or a vascular bronchopulmonary dysplasia phenotype. Induced pluripotent stem cells (iPSCs) are one of the most exciting breakthroughs of the past decade. Patient-specific iPSCs can be derived from somatic cells and differentiated into any cell type. iPSCs can be capitalized upon to develop personalized regenerative cell products for surfactant protein deficiencies-lethal lung disorders without treatment-that affect a single gene in a single cell type and thus lend themselves to phenotype-specific cell replacement. While the clinical translation has begun, more needs to be learned about the biology of these repair cells to make this translation successful. | {
"pile_set_name": "PubMed Abstracts"
} |
Leptin-induced downregulation of the rat hippocampal somatostatinergic system may potentiate its anorexigenic effects.
The learning and memory mechanisms in the hippocampus translate hormonal signals of energy balance into behavioral outcomes involved in the regulation of food intake. As leptin and its receptors are expressed in the hippocampus and somatostatin (SRIF), an orexigenic neuropeptide, may inhibit leptin-mediated suppression of food intake in other brain areas, we asked whether chronic leptin infusion induces changes in the hippocampal somatostatinergic system and whether these modifications are involved in leptin-mediated effects. We studied 18 male Wistar rats divided into three groups: controls (C), treated intracerebroventricularly (icv) with leptin (12 μg/day) for 14 days (L) and a pair-fed group (PF) that received the same amount of food consumed by the L group. Food restriction increased whereas leptin decreased the hippocampal SRIF receptor density, due to changes in SRIF receptor 2 protein levels. These changes in the PF group were concurrent with an increase of hippocampal G protein-coupled receptor kinase 2 protein levels and activation of Akt and cyclic AMP response element binding protein. The inhibitory effect of SRIF on adenylyl cyclase (AC) activity, however, was decreased in L rats, coincident with lower G inhibitory α3 and higher AC-I levels as well as signal transducer and activator of transcription factor 3 activation. In addition, 20 male Wistar rats were included to analyze whether the leptin antagonist L39A/D40A/F41A and the SRIF receptor agonist SMS 201-995 modify SRIF signaling and food intake, respectively. Administration of L39A/D40A/F41A reversed changes in SRIF signaling, whereas SMS 201-995 ameliorated food consumption in L. Altogether, these results suggest that increased somatostatinergic tone in PF rats may be a mechanism to improve the hippocampal orexigenic effects in a situation of metabolic demand, whereas down-regulation of this system in L rats may represent a mechanism to enhance the anorexigenic effects of leptin. | {
"pile_set_name": "PubMed Abstracts"
} |
Hemorrhagic cystitis in a patient receiving conventional doses of dacarbazine for metastatic malignant melanoma: case report and review of the literature.
Hemorrhagic cystitis is a potentially life-threatening complication in patients receiving cancer therapy. This urologic emergency is commonly associated with the chemotherapeutic use of oxazaphosphorine alkylating agents. This report describes a case of hemorrhagic cystitis associated with dacarbazine treatment. A 63-year-old man with asymptomatic metastatic malignant melanoma received 3 cycles of dacarbazine (600-850 mg/m2) monochemotherapy, each 3 weeks apart. Two weeks after the third cycle, he presented with gross hematuria and mild dysuria. Physical examination revealed no significant finding. Hematuria was confirmed by urinalysis, and urinary infection was excluded by repeated urine cultures. Ultrasonography revealed diffuse bladder wall thickening with no discrete mass or ulceration. Cystoscopy findings revealed generalized inflammation and edema of the mucosa of the bladder, confirming the diagnosis of hemorrhagic cystitis. The patient's gross hematuria continued for 2 weeks and then completely resolved with supportive care. Two weeks after complete resolution, the patient experienced 2 transient episodes of gross hematuria that lasted a few hours and subsided spontaneously. Dacarbazine is currently considered the standard first-line treatment in patients with advanced malignant melanoma. At standard prescribed doses (a single dose of 850-1000 mg/m2 or 250 mg/m2 for 5 days per cycle), dacarbazine is a reasonably well tolerated chemotherapeutic drug; nausea, vomiting, and myelosuppression are the most common adverse effects. Association of dacarbazine with hemorrhagic cystitis has not been reported previously (in a PubMed literature search from 1950-2006), and only 1 case report associates temozolomide (an analog of dacarbazine) with hemorrhagic cystitis. Based on the Naranjo adverse drug reactions probability scale, an objective assessment revealed dacarbazine to be a probable cause of hemorrhagic cystitis in this case. This case report suggests that dacarbazine at conventional doses was a probable cause of hemorrhagic cystitis. Regular urinalysis and early intervention are recommended, as a means of detecting early hematuria and subsequently reducing or discontinuing dacarbazine treatment. Adequate hydration before, during, and after dacarbazine administration may be useful in preventing this complication. | {
"pile_set_name": "PubMed Abstracts"
} |
Subcellular distribution and antifungal effects of fluconazole in human phagocytic cells. Demonstration of the antifungal agent in neutrophil polymorphonuclear leucocytes and monocytes by autoradiography and electron micrography.
Electron microscopic autoradiography was used to demonstrate the presence of [3H] fluconazole (CAS 86386-73-4) in neutrophils and monocytes isolated from volunteers. Quantitative analysis of the autoradiographs showed significant accumulation of fluconazole in both phagocytic cells. The distribution of fluconazole was equal in the different intracellular compartments such as cytoplasm and nucleus. Fluconazole (20 micrograms/ml) induced ultrastructural changes in Candida albicans cells which had been phagocytized by neutrophils or monocytes (macrophages) in vitro. Particularly, changes in the plasma membrane and in the cytoplasmic structure of the intraphagocytic yeast cells were observed electron microscopically. | {
"pile_set_name": "PubMed Abstracts"
} |
Quantitative phase imaging in flows with high resolution holographic diffraction grating.
This paper proposes quantitative phase imaging by using a high resolution holographic grating for generating a four-wave shearing interferogram. The high-resolution holographic grating is designed in a "kite" configuration so as to avoid parasitic mixing of diffraction orders. The selection of six diffraction orders in the Fourier spectrum of the interferogram allows reconstructing phase gradients along specific directions. The spectral analysis yields the useful parameters of the reconstruction process. The derivative axes are exactly determined whatever the experimental configurations of the holographic grating. The integration of the derivative yields the phase and the optical thickness. Demonstration of the proposed approach is carried out for the case of the analysis of the supersonic flow of a small vertical jet, 5.56mm in diameter. The experimental results compared with those obtained with digital holography exhibit a very good agreement. | {
"pile_set_name": "PubMed Abstracts"
} |
The genomes of fermentative Saccharomyces.
Many different yeast species can take part in spontaneous fermentations, but the species of the genus Saccharomyces, including Saccharomyces cerevisiae in particular, play a leading role in the production of fermented beverages and food. In recent years, the development of whole-genome scanning techniques, such as DNA chip-based analysis and high-throughput sequencing methods, has considerably increased our knowledge of fermentative Saccharomyces genomes, shedding new light on the evolutionary history of domesticated strains and the molecular mechanisms involved in their adaptation to fermentative niches. Genetic exchange frequently occurs between fermentative Saccharomyces and is an important mechanism for generating diversity and for adaptation to specific ecological niches. We review and discuss here recent advances in the genomics of Saccharomyces species and related hybrids involved in major fermentation processes. | {
"pile_set_name": "PubMed Abstracts"
} |
Synthesis and magnetic properties of cobalt-iron/cobalt-ferrite soft/hard magnetic core/shell nanowires.
A straightforward method for the synthesis of CoFe2.7/CoFe2O4 core/shell nanowires is described. The proposed method starts with a conventional pulsed electrodeposition procedure on alumina nanoporous template. The obtained CoFe2.7 nanowires are released from the template and allowed to oxidize at room conditions over several weeks. The effects of partial oxidation on the structural and magnetic properties were studied by x-ray spectrometry, magnetometry, and scanning and transmission electron microscopy. The results indicate that the final nanowires are composed of 5 nm iron-cobalt alloy nanoparticles. Releasing the nanowires at room conditions promoted surface oxidation of the nanoparticles and created a CoFe2O4 shell spinel-like structure. The shell avoids internal oxidation and promotes the formation of bi-magnetic soft/hard magnetic core/shell nanowires. The magnetic properties of both the initial single-phase CoFe2.7 nanowires and the final core/shell nanowires, reveal that the changes in the properties from the array are due to the oxidation more than effects associated with released processes (disorder and agglomeration). | {
"pile_set_name": "PubMed Abstracts"
} |
Biomechanical analysis of forces sustained by iliac screws in spinal instrumentation for deformity treatment: preliminary results.
Iliac screws used in long instrumentation for deformity treatment are subject to large forces, which may sometimes lead to fixation failures (intra- and postoperatively). The objective of this study was to analyze the biomechanics of iliac screw fixations. The study was based on a patient-specific simulation of a neuromuscular scoliosis case with a long instrumentation to the pelvis. A multi body flexible model was created using a preoperative 3D reconstructed spine and pelvis. The side bending radiographs were used to personalize the mechanical properties. The instrumentation construct was modeled as rigid bodies and flexible beams connected by kinematic joints. Three instrumentation parameters were studied: the connector length, the inter rod connectors and the use of sacral screws. The simulations showed that the forces and torques at the iliac screws were lowered by 9% and 25% respectively by reducing the lateral connector length (from 20 to 10 mm). An inter rod connector did not significantly reduce the iliac screw loads. Sacral screws reduced the functional loads on the iliac screws, but hardware related problems may be shifted onto the sacral screws. Sacral screws in conjunction with inter rod connectors reduced the loads at iliac screws without overloading the sacral screws. The preliminary results showed that the forces at the iliac screws could be lowered through different instrumentation parameters. In the next step of the study, the model validation will be further completed and used to evaluate other instrumentation factors by means of an experimental design framework. The knowledge of loading biomechanics at the iliac screw fixation is important for finding solutions to reduce the risk of failure, such as improving preoperative planning, instrumentation techniques and iliac screw construct design. | {
"pile_set_name": "PubMed Abstracts"
} |
Arthropod colonization of land--linking molecules and fossils in oribatid mites (Acari, Oribatida).
Terrestrial fossils that document the early colonization of land are scarce for >100 my after the Cambrian explosion. This raises the question whether life on land did not exist or just did not fossilize. With a molecular dating technique, we analyzed the origin of terrestrial chelicerate microarthropods (Acari, Oribatida) which have a fossil record since the Middle Devonian that is exceptional among soil animals. Our results suggest that oribatid mites originated in the Precambrian (571+/-37 mya) and that the radiation of basal groups coincides with the gap in the terrestrial fossil record between the Cambrian explosion and the earliest fossilized records of continental ecosystems. Further, they suggest that the colonization of land started via the interstitial, approximately 150 my earlier than the oldest fossils of terrestrial ecosystems. Overall, the results imply that omnivorous and detritivorous arthropods formed a major component in early terrestrial food webs, thereby facilitating the invasion of terrestrial habitats by later colonizers of higher trophic levels. | {
"pile_set_name": "PubMed Abstracts"
} |
Exogenous nitric oxide induces apoptosis in Toxoplasma gondii tachyzoites via a calcium signal transduction pathway.
The mechanism by which nitric oxide (NO)-dependent cytotoxicity acts against Toxoplasma gondii tachyzoites is poorly understood. An NO donor, sodium nitroprusside (SNP), was used to induce death in T. gondii tachyzoites in vitro as a model for investigating (i) whether NO is capable of inducing apoptosis-like death in tachyzoites and (ii) whether a calcium signal transduction pathway is involved. Exposure to 2 mM SNP resulted in a pattern of tachyzoite death that shares many features with metazoan apoptosis and it may involve a calcium signal transduction pathway. Motility and cell survival in these parasites showed a gradual decline with increasing levels of SNP. Features common to metazoan apoptosis are observed after exposure to 2 mM SNP. Ethylene glycol bis-(beta-aminoethyl ether)-N,N,N',N'-tetra-acetic acid (EGTA), Verapamil and bis-(o-aminophenoxy) ethane-N,N,N',N'-tetra-acetic acid/acetoxymethyl ester (BAPTA/AM) partially increased the cell survival concomitant with decreased [Ca2+]i in cells exposed to SNP. An NO scavenger (N-acetylcysteine), the analogue of SNP (devoid of NO), inhibited the rate of apoptosis after SNP treatment compared with SNP treatment without scavenger, but alone did not induce apoptosis. Taken together, the results indicate that SNP is capable of inducing apoptosis in T. gondii tachyzoites via a calcium signal transduction pathway. | {
"pile_set_name": "PubMed Abstracts"
} |
The role of the integrin LFA-1 in T-lymphocyte migration.
A successful immune response depends on the migration of lymphocytes into lymph nodes or inflamed tissues where they make contact with antigen-presenting cells. We are interested in how one member of the integrin family, leukocyte function-associated antigen-1 (LFA-1), controls the function and, in particular, the migration of immune cells. We find that this integrin operates not only as an adhesion receptor for T lymphoblasts (T cells) but also induces their migration in vitro at approximately 15 microm/min. Migration requires active myosin light chain kinase at the leading edge and Rho kinase at the trailing edge of the cell. Two active conformations of LFA-1 are differently distributed on the T-cell membrane and regulate independent aspects of migration. High-affinity LFA-1 is located in a midcell 'focal zone' and influences the speed of migration, whereas intermediate affinity LFA-1 controls leading edge adhesions. Manipulating LFA-1 conformation in vivo can be performed, for example, by creating the active conformation in a transgenic mouse, and this model gives further insight into the role of LFA-1 in migration. In humans, the beneficial effect of functioning CD18 integrins in combating infections in vivo is illustrated by rare patients displaying two forms of leukocyte adhesion deficiency. In summary, we speculate that T cells have evolved a mode of rapid migration that is of paramount importance in achieving the high-speed immune surveillance upon which depends the body's protection against diverse invaders from pathogens to cancer cells. | {
"pile_set_name": "PubMed Abstracts"
} |
Bitter peptides and bitter taste receptors.
Bitter peptides are a structurally diverse group of oligopeptides often generated in fermented, aged, and hydrolyzed food products that make them unfavorable for consumption. Humans perceive bitterness by a repertoire of 25 human bitter receptors, termed T2Rs. Knowledge of the structural features of bitter receptors and of the factors that stimulate bitter receptors will aid in understanding the mechanism responsible for bitter taste perception. This article reviews the current knowledge regarding structural features of bitter peptides and bitter taste receptors. | {
"pile_set_name": "PubMed Abstracts"
} |
When biomolecules meet graphene: from molecular level interactions to material design and applications.
Graphene-based materials have attracted increasing attention due to their atomically-thick two-dimensional structures, high conductivity, excellent mechanical properties, and large specific surface areas. The combination of biomolecules with graphene-based materials offers a promising method to fabricate novel graphene-biomolecule hybrid nanomaterials with unique functions in biology, medicine, nanotechnology, and materials science. In this review, we focus on a summarization of the recent studies in functionalizing graphene-based materials using different biomolecules, such as DNA, peptides, proteins, enzymes, carbohydrates, and viruses. The different interactions between graphene and biomolecules at the molecular level are demonstrated and discussed in detail. In addition, the potential applications of the created graphene-biomolecule nanohybrids in drug delivery, cancer treatment, tissue engineering, biosensors, bioimaging, energy materials, and other nanotechnological applications are presented. This review will be helpful to know the modification of graphene with biomolecules, understand the interactions between graphene and biomolecules at the molecular level, and design functional graphene-based nanomaterials with unique properties for various applications. | {
"pile_set_name": "PubMed Abstracts"
} |
A Gas-Phase Reaction Cell for Modern Atom Probe Systems.
In this work, we demonstrate a new system for the examination of gas interactions with surfaces via atom probe tomography. This system provides capability of examining the surface and subsurface interactions of gases with a wide range of specimens, as well as a selection of input gas types. This system has been primarily developed to aid the investigation of hydrogen interactions with metallurgical samples, to better understand the phenomenon of hydrogen embrittlement. In its current form, it is able to operate at pressures from 10-6 to 1000 mbar (abs), can use a variety of gasses, and is equipped with heating and cryogenic quenching capabilities. We use this system to examine the interaction of hydrogen with Pd, as well as the interaction of water vapor and oxygen in Mg samples. | {
"pile_set_name": "PubMed Abstracts"
} |
High prevalence of ESBL-positive bacteria in an obstetrics emergency hospital and neonatal care unit-Haiti, 2016.
A point-prevalence survey of mothers and neonates admitted to an obstetrics emergency hospital in Port-au-Prince, Haiti, revealed that 13 of 127 gram-negative bacteria isolates (10%) from rectal swabs were ESBL-positive in women and 30 of 59 gram-negative bacteria isolates (51%) from rectal swabs were ESBL-positive in neonates. Length of hospital stay and antibiotic consumption were risk factors for ESBL colonization. | {
"pile_set_name": "PubMed Abstracts"
} |
Investigation of lipid modifications in J774 macrophages by vibrational spectroscopies after eicosapentaenoic acid membrane incorporation in unloaded and cholesterol-loaded cells.
Atherosclerosis is an inflammatory disease of the arterial wall caused by the formation of an atheroma plaque in the vessel wall. The uptake of modified LDL lipoproteins by sub-endothelial macrophages induces the latter's transformation into foam cells, which is the key step of atheroma plaque formation. The modifications of neutral lipids caused by foam cells formation are marked by the appearance of lipid droplets. Polyunsaturated fatty acids (PUFAs) incorporation into membrane phospholipids (PL) modifies their composition, which may influence membrane protein functions. The incorporation of eicosapentaenoic acid (EPA) reduces the anti-atherogenic ABCA1 (ATP Binding Cassette transporter A1) pathway and induces PLs modifications. In order to study lipids directly in the cell environment, a comparative study is conducted by vibrational spectroscopies on murine macrophages J774, loaded or not with cholesterol, which were enriched or not with eicosapentaenoic acid (EPA). The study enabled to identify changes in the spectral signature after cells enrichment with fatty acid (FA) relying only on chemometric analysis without deuterium labelling. Results highlighted spectral changes in the regions attributed to lipids associated to triglycerides, phospholipids and cholesterol in both Raman and IR. | {
"pile_set_name": "PubMed Abstracts"
} |
Development of a Newcastle disease virus vector expressing a foreign gene through an internal ribosomal entry site provides direct proof for a sequential transcription mechanism.
In the present study, we developed a novel approach for foreign gene expression by Newcastle disease virus (NDV) from a second ORF through an internal ribosomal entry site (IRES). Six NDV LaSota strain-based recombinant viruses vectoring the IRES and a red fluorescence protein (RFP) gene behind the nucleocapsid (NP), phosphoprotein (P), matrix (M), fusion (F), haemagglutinin-neuraminidase (HN) or large polymerase (L) gene ORF were generated using reverse genetics technology. The insertion of the second ORF slightly attenuated virus pathogenicity, but did not affect ability of the virus to grow. Quantitative measurements of RFP expression in virus-infected DF-1 cells revealed that the abundance of viral mRNAs and red fluorescence intensity were positively correlated with the gene order of NDV, 3'-NP-P-M-F-HN-L-5', proving the sequential transcription mechanism for NDV. The results herein suggest that the level of foreign gene expression could be regulated by selecting the second ORF insertion site to maximize the efficacy of vaccine and gene therapy. | {
"pile_set_name": "PubMed Abstracts"
} |
[Variable tandem repeat VcA of Vibrio cholerae].
Computer analysis revealed seven potential variable-number tandem-repeat (VNTR) loci in the Vibrio cholerae genome. Specific primers were designed to amplify locus VcA located on chromosome 2 and containing a TGCTGT repeat. The locus was found in all tested strains from a V. cholerae strain collection, the repeat number varying 3 to 23. In total, 14 VcA alleles were observed. The VcA locus was proposed as a marker for the molecular typing of V. cholerae strains. | {
"pile_set_name": "PubMed Abstracts"
} |
Thyroid uptake of MIBG in Sipple's syndrome.
The use of the adrenomedullary tracer metaiodobenzylguanidine (MIBG) in the localization of medullary carcinoma of the thyroid (MCT) is based on the embryologic relationship of the APUD cell series. The authors report the results obtained in six patients with MCT: two had Sipple's syndrome and four sporadic forms of the disease. MIBG uptake by the CMT was observed in both cases of Sipple's syndrome and in only one of the other cases. Scintigraphic detection seems to depend on the clinical features, the size of the tumour and also on the part played by its secretory function. MCT would thus appear to be more frequently visualized by MIBG in cases of Sipple's syndrome than in sporadic cases. The procedure therefore seems useful in the diagnosis, follow up and even in the treatment of MCT. | {
"pile_set_name": "PubMed Abstracts"
} |
Sleep deprivation in narcoleptic subjects: effect on sleep stages and EEG power density.
Sleep of 8 narcoleptic and 8 control subjects was recorded under baseline (i.e., prior wakefulness 16 h) and after 24 h without sleep. During both baseline and recovery total sleep time and stage 2 non-REM sleep were significantly decreased in narcoleptic subjects. Slow wave activity (i.e., EEG power density in the range of 0.75-4.5 Hz) decayed exponentially during baseline and after sleep deprivation in both narcoleptic and control subjects. During both baseline and recovery EEG power density in delta and sigma frequencies in non-REM sleep was enhanced in narcoleptic subjects relative to controls. In REM sleep differences in the same direction were present in delta and beta frequencies. After sleep deprivation EEG power density in non-REM sleep was elevated in delta and some higher frequencies in both patients and controls, but the response to sleep deprivation was stronger in narcoleptic subjects. These data show that in narcoleptic subjects regulatory processes underlying non-REM sleep homeostasis are operative and indicate that the response to sleep deprivation is stronger than in control subjects. | {
"pile_set_name": "PubMed Abstracts"
} |
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